Conductive gel release and distribution devices

ABSTRACT

A gel deployment device for use with an electrotherapy system is provided. The device includes a plurality of gel reservoirs disposed on a substrate, each of the plurality of gel reservoirs containing conductive gel. Each of the gel reservoirs are positioned adjacent to at least one seal such that the seal restricts flow of the conductive gel. The seal can be configured to release the conductive gel from the gel reservoir in response to pressure being applied about a perimeter of the seal at, for example, multiple points about the perimeter or substantially equally about the perimeter of the seal. In an example, each gel reservoir can be shaped such that the gel reservoir partially or fully surrounds a seal. In another example, multiple gel reservoirs can be arranged in clusters such that the multiple gel reservoirs are positioned about a single seal.

BACKGROUND

The present disclosure is directed to medical therapy systems, and moreparticularly, to electrode systems such as therapy electrodes includinggel release and distribution mechanisms.

Cardiac arrest and other cardiac health ailments are a major cause ofdeath worldwide. Various resuscitation efforts aim to maintain thebody's circulatory and respiratory systems during cardiac arrest in anattempt to save the life of the victim. The sooner these resuscitationefforts begin, the better the victim's chances of survival. Theseefforts are expensive and have a limited success rate, and cardiacarrest, among other conditions, continues to claim the lives of victims.

To protect against cardiac arrest and other cardiac health ailments,some at-risk subjects may use a non-invasive bodily-attached ambulatorymedical monitoring and treatment device, such as the LifeVest® wearablecardioverter defibrillator available from ZOLL Medical Corporation. Toremain protected, the subject wears the device nearly continuously whilegoing about their normal daily activities, while awake, and whileasleep.

Such medical devices work by providing one or more shocks to a patient.Prior to delivering the one or more shocks, a conductive gel deploymentdevice can release a conductive gel about a conductive surface of atherapy electrode such that the one or more shocks can be directed fromthe therapy electrode to the patient's skin.

SUMMARY

In some embodiments, a gel deployment device for use with anelectrotherapy system is provided. The device includes a substrate, aplurality of gel reservoirs disposed on the substrate, and at least oneconductive surface. Each of the plurality of gel reservoirs comprises avolume of a conductive gel and are positioned on the substratesubstantially adjacent to a seal. The seal is configured to release theconductive gel from at least one of the plurality of gel reservoirs inresponse to pressure being applied about a perimeter of the seal. Theconductive surface is configured to come into contact with the releasedconductive gel and to deliver a therapeutic current to a body of apatient.

Preferred and non-limiting embodiments or aspects of the presentinvention will now be described in the following numbered clauses:

Clause 1. A gel deployment device for use with an electrotherapy system,the device comprising: a substrate; a plurality of gel reservoirsdisposed on the substrate, each of the plurality of gel reservoirscomprising a volume of a conductive gel and positioned substantiallyadjacent to a seal; wherein the seal is configured to release theconductive gel from at least one of the plurality of gel reservoirs inresponse to pressure being applied about a perimeter of the seal; and atleast one conductive surface configured to come into contact with thereleased conductive gel and to deliver a therapeutic current to a bodyof a patient.

Clause 2. The device of clause 1, wherein the conductive gel is capableof conducting the therapeutic current from the at least one conductivesurface to the patient's skin.

Clause 3. The device of clause 1 or 2, wherein the at least oneconductive surface comprises at least one opening configured todistribute the therapeutic current through the at least one conductivesurface.

Clause 4. The device of any of clauses 1-3, wherein the substratecomprises one or more ventilation holes configured to facilitate airflow through the gel deployment device.

Clause 5. The device of any of clauses 1-4, wherein at least one of theplurality of gel reservoirs is oriented on the substrate such that theat least one of the plurality of gel reservoirs surrounds the seal.

Clause 6. The device of clause 5, wherein the at least one of theplurality of gel reservoirs is configured to exert an applied pressureat multiple points about the perimeter of the surrounded seal.

Clause 7. The device of clause 5 or 6, wherein the at least one of theplurality of gel reservoirs is configured to exert an applied pressuresubstantially equally about the perimeter of the surrounded seal.

Clause 8. The device of any of clauses 5-7, wherein each of theplurality of gel reservoirs comprises a donut shape defining an opencenter portion, wherein the seal is positioned within the open centerportion of each of the donut shaped gel reservoirs.

Clause 9. The device of any of clauses 5-8, wherein each of theplurality of gel reservoirs comprises a polygon shape defining an opencenter portion, wherein the seal is positioned within the open centerportion of each of the polygon shaped gel reservoirs.

Clause 10. The device of any of clauses 1-9, wherein at least one of theplurality of gel reservoirs is shaped such that it partially surroundsthe seal.

Clause 11. The device of any of clauses 1-10, further comprising atleast one reservoir cluster comprising two or more gel reservoirs.

Clause 12. The device of clause 11, wherein the at least one reservoircluster is configured such that the two or more gel reservoirs arepositioned about a center point, thereby defining an open centerportion, wherein the seal is positioned within the open center portionof the at least one reservoir cluster.

Clause 13. The device of clause 12, wherein, upon application of thedistributed pressure, the seal positioned within the open center portionof the at least one reservoir cluster is configured to release theconductive gel from each of the two or more of the plurality of gelreservoirs in the at least one reservoir cluster substantiallysimultaneously.

Clause 14. The device of any of clauses 1-13, further comprising atleast one fluid channel, wherein a first end of the at least one fluidchannel is connected to each of the plurality of gel reservoirs.

Clause 15. The device of clause 14, wherein a second end of the at leastone fluid channel is connected to a pressure source configured toprovide pressure through the at least one fluid channel to each of theplurality of gel reservoirs.

Clause 16. The device of any of clauses 1-15, wherein the plurality ofconductive gel reservoirs is configured to collectively store between 3ml and 20 ml of conductive gel.

Clause 17. The device of any of clauses 1-16, wherein each of theplurality of conductive gel reservoirs is configured to store between0.50 and 4.0 ml of conductive gel.

Clause 18. The device of any of clauses 1-17, wherein the pressure beingapplied about the perimeter of the seal is between 4 psi and 30 psi.

Clause 19. A system for providing therapy to a patient, the systemcomprising: a garment; a monitor configured to monitor at least onephysiological parameter of a patient; and a plurality of therapyelectrodes operably connected to the monitor and disposed in thegarment, each of the plurality of therapy electrodes comprising a geldeployment device for deploying conductive gel onto skin of the patient,the gel deployment device comprising a plurality of gel reservoirsdisposed on a substrate, wherein each of the plurality of gel reservoirscomprises a volume of the conductive gel and is positioned substantiallyadjacent to a seal, wherein the seal is configured to release the volumeof gel from the gel reservoir in response to a distributed pressurebeing applied about a perimeter of the seal, and at least one conductivesurface configured to come into contact with the released conductive geland deliver a therapeutic shock.

Clause 20. The system of clause 19, wherein at least one of theplurality of gel reservoirs is oriented on the substrate such that itsurrounds the seal.

Clause 21. The system of clause 19 or 20, further comprising at leastone reservoir cluster comprising two or more gel reservoirs.

Clause 22. The system of clause 21, wherein the at least one reservoircluster is configured such that the two or more gel reservoirs arepositioned about a center point, thereby defining an open center portionsuch that the seal of the two or more gel reservoirs is positionedwithin the open center portion of the at least one reservoir cluster.

Clause 23. A system for providing therapy to a patient, the systemcomprising: a garment; a monitor configured to monitor at least onephysiological parameter of a patient; and a plurality of therapyelectrodes operably connected to the monitor and disposed in thegarment, each of the plurality of therapy electrodes comprising a geldeployment device for deploying conductive gel onto skin of the patient,the gel deployment device comprising a plurality of gel reservoirsdisposed on a substrate, wherein each of the plurality of gel reservoirscomprises between 0.5 ml and 4.0 ml of the conductive gel and ispositioned substantially adjacent to a seal, wherein the seal isconfigured to release the conductive gel from the gel reservoir inresponse to a distributed pressure of about 4 psi to 30 psi beingapplied about a perimeter of the seal, and at least one conductivesurface configured to come into contact with the released conductive geland deliver a therapeutic shock.

Clause 24. The system of clause 23, wherein at least one of theplurality of gel reservoirs is oriented on the substrate such that itsurrounds the seal.

Clause 25. The system of clause 23 or 24, further comprising at leastone reservoir cluster comprising two or more gel reservoirs.

Clause 26. A gel deployment device for use with an electrotherapysystem, the device comprising: a substrate; at least one gel reservoirdisposed on the substrate, the at least one gel reservoir comprising avolume of conductive gel and is positioned substantially adjacent to aseal, wherein the seal is configured to release the volume of conductivegel from the at least one gel reservoir in response to a pressure beingapplied to at least a portion of the seal; at least one gel conduitconfigured to fluidly connect to the at least one gel reservoir anddirect flow of the released conductive gel from the at least one gelreservoir to one or more exit ports disposed on the substrate; and atleast one conductive surface configured to come into contact with thereleased conductive gel and deliver a therapeutic shock.

Clause 27. The device of clause 26, wherein the one or more exit portsare spaced apart on the substrate to provide for even distribution ofthe conductive gel on the conductive surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of at least one example are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide an illustration anda further understanding of the various aspects and examples, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of any particular example. Thedrawings, together with the remainder of the specification, serve toexplain principles and operations of the described and claimed aspectsand examples. In the figures, each identical or nearly identicalcomponent that is illustrated in various figures is represented by alike numeral. For purposes of clarity, not every component may belabeled in every figure.

FIG. 1 depicts a wearable medical device, in accordance with an exampleof the present disclosure.

FIG. 2A depicts a plan view of a therapy electrode that can be used withthe wearable medical device of FIG. 1.

FIG. 2B depicts a conductive gel reservoir design for use with a therapyelectrode such as the therapy electrode shown in FIG. 2A.

FIG. 2C depicts an exploded view of the therapy electrode of FIG. 2A.

FIGS. 3A-3D depict a conductive gel reservoir and adhesive sealassembly, in accordance with an example of the present disclosure.

FIG. 4A depicts a plan view of a therapy electrode, in accordance withan example of the present disclosure.

FIG. 4B depicts an exploded view of the therapy electrode of FIG. 3A.

FIG. 5 depicts an example of a conductive gel reservoir, in accordancewith an example of the present disclosure.

FIG. 6A depicts a plan view of a therapy electrode, in accordance withan example of the present disclosure.

FIG. 6B depicts an exploded view of the therapy electrode of FIG. 5A.

FIG. 7 depicts an interface between a therapy electrode and a patient'sskin in accordance with an example of the present disclosure.

FIG. 8 depicts a schematic diagram illustrating various components of anexternal medical device in accordance with an example of the presentdisclosure.

DETAILED DESCRIPTION

This disclosure relates to an improved conductive gel deployment deviceconfigured to provide for release and distribution of conductive gel foruse with, for example, an electrode of an ambulatory electrotherapysystem or device such as a wearable defibrillator as described infurther detail below.

Wearable defibrillators operate by continuously or substantiallycontinuously monitoring one or more physiological signals of anambulatory patient and, upon determination that treatment is required,delivering one or more therapeutic electrical pulses to the patient. Forexample, a wearable defibrillator can monitor a cardiac signal of thepatient via at least one sensing electrode, and provide the therapeuticelectrical pulses to the patient via one or more electrotherapyelectrodes. Prior to delivering the one or more therapeutic pulses, thewearable defibrillator can be configured to release conductive gel onthe patient's skin, e.g., to lower an impedance between the electrodeand the patient's skin. Such conductive gel can be stored in aconductive gel deployment device which can be configured to deploy thegel when needed.

In traditional designs, for example, a conductive gel deployment devicecan include a gel reservoir that is associated with an exit portconfigured to direct flow of conductive gel from the gel reservoir to aconductive surface of the therapy electrode. An adhesive seal positionedbetween the gel reservoir and its associated exit port is configured toprevent premature release of the conductive gel. In such designs, only aportion of the gel reservoir is configured to be in contact with theadhesive seal, thereby resulting in a smaller fluid pathway for flow ofthe conductive gel when released. As such, conductive gel flow from thegel reservoirs through the adhesive seals is reduced as a result of thelimited contact and smaller fluid pathway. In a situation where a quickdeployment of a large volume of conductive gel is desirable, theconductive gel flow can be unnecessarily slowed as a result of thelimited contact between the gel reservoirs and the adhesive seals.

Additionally, as there is limited contact between the gel reservoirs andthe adhesive seals, any pressure applied to the gel reservoirs (e.g., asa result of a patient wearing the garment 110 and, for example, leaningagainst or otherwise pressing on the conductive gel reservoirs) couldresult in a premature failure of the adhesive seal and unwanted releaseof the conductive gel. As described herein in greater detail below, thepresent disclosure describes configurations that partially or fullysurround an adhesive seal with a gel reservoir, thereby distributingpressure applied by the gel reservoir about a larger portion of theadhesive seal (up to and including a full perimeter of, for example, acircular adhesive seal) and reducing the likelihood of a prematurefailure of the adhesive seal. In another implementation, a plurality ofexit ports is associated with a gel reservoir to allow for increasedvolume in the flow of conductive fluid on to the patient's skin (see,e.g., FIG. 5A and associated description below). Also, gel conduits areprovided to physically separate the gel reservoir and associated one ormore adhesive seals from the exit port to prevent premature leakage ofthe conductive gel.

As described in detail below, various configurations can be used for aconductive gel deployment device that include various numbers andarrangements of conductive gel reservoirs and seals. In some examples, aseries of conductive gel reservoirs are disposed on a substrate of thegel deployment device. Each conductive gel reservoir can be shaped suchthat it defines an open center portion. For example, each of theconductive gel reservoirs can have a substantially donut shape or atoroid shape (e.g., a geometric shape such as a circle or square rotatedabout a central point to define a three-dimensional shape), whichdefines an open center portion. The shapes and arrangements describedherein can vary as needed to support one or more goals of theconfigurations below. For example, other shapes that define an opencenter portion can be used, including a rectangle, square, triangle,polygon, etc. Further, an external shape of the conductive gelreservoirs can differ from a shape of the open center portion (e.g., theexternal shape of the reservoir can be substantially square while theshape of the open center portion can be substantially circular). In animplementation, a seal, such as a peelable adhesive seal, can bepositioned within the open center portion. For example, if theconductive gel reservoir has a donut shape, the adhesive seal can beconfigured to have a ring shape. The adhesive seal can be configured torelease a conductive gel contained within the conductive gel reservoirin response to a distributed pressure being applied about a perimeter ofthe adhesive seal. After release, the conductive gel can be distributedabout a conductive surface of the therapy electrode prior to delivery ofa therapeutic current to a patient.

In certain implementations, multiple conductive gel reservoirs can bearranged into a reservoir cluster. An adhesive seal, such as thering-shaped peelable adhesive seal described above, can be positioned ata center point in the middle of the reservoir cluster. In response to anapplied distributed pressure, the adhesive seal can be configured torelease a conductive gel from each of the conductive gel reservoirs inthe reservoir cluster substantially simultaneously.

In some examples, one or more conductive gel reservoirs can beassociated with one or more corresponding conductive gel conduits. Incertain implementations, an adhesive seal can be configured to release aconductive gel from the one or more reservoirs. The one or moreconductive gel conduits can be connected to the one or more gelreservoirs such that, upon release of the conductive gel, the one ormore conductive gel conduits can direct flow of the conductive gel tomultiple exit ports for distribution of the conductive gel.

It should be noted that the above described conductive gel deploymentdevices are merely shown as introductory examples, and additionaldetails are provided in the following discussions of the figures.

Example Medical Devices

FIG. 1 illustrates an example medical device 100 that is external,ambulatory, and wearable by a patient 102, and configured to implementone or more configurations described herein. For example, the medicaldevice 100 can be a non-invasive medical device configured to be locatedsubstantially external to the patient. Such a device can be, forexample, an ambulatory medical device that is capable of and designedfor moving with the patient as the patient goes about his or her dailyroutine. For example, the medical device 100 as described herein can bean external electrotherapy device that is bodily-attached to the patientsuch as the LifeVest® wearable cardioverter defibrillator available fromZOLL® Medical Corporation. Such wearable defibrillators typically areworn nearly continuously or substantially continuously for two to threemonths at a time. During the period of time in which they are worn bythe patient, the wearable defibrillator can be configured tocontinuously or substantially continuously monitor the vital signs ofthe patient and, upon determination that treatment is required, can beconfigured to deliver one or more therapeutic electrical pulses to thepatient. For example, such therapeutic shocks can be pacing,defibrillation, or transcutaneous electrical nerve stimulation (TENS)pulses.

The medical device 100 can include one or more of the following: agarment 110, one or more sensing electrodes 112 (e.g., ECG electrodes),one or more therapy electrodes 114, a medical device controller 120, aconnection pod 130, a patient interface pod 140, a belt 150, or anycombination of these. In some examples, at least some of the componentsof the wearable medical device 100 can be configured to be affixed tothe garment 110 (or in some examples, permanently integrated into thegarment 110), which can be worn about the patient's torso.

The controller 120 can be operatively coupled to the sensing electrodes112, which can be affixed to the garment 110, e.g., assembled into thegarment 110 or removably attached to the garment, e.g., using hook andloop fasteners. In some implementations, the sensing electrodes 112 canbe permanently integrated into the garment 110. The controller 120 canbe operatively coupled to the therapy electrodes 114. For example, thetherapy electrodes 114 can also be assembled into the garment 110, or,in some implementations, the therapy electrodes 114 can be permanentlyintegrated into the garment 110. Additionally, the therapy electrodes114 can include one or more conductive gel deployment devices such asthe devices described herein and, as other examples, devices describedin U.S. Patent Application Publication No. 2012/0150164 entitled“Therapeutic Device Including Acoustic Sensor,” the content of which isincorporate herein by reference.

Component configurations other than those shown in FIG. 1 are possible.For example, the sensing electrodes 112 can be configured to be attachedat various positions about the body of the patient 102. The sensingelectrodes 112 can be operatively coupled to the medical devicecontroller 120 through the connection pod 130. In some implementations,the sensing electrodes 112 can be adhesively attached to the patient102. In some implementations, the sensing electrodes 112 and therapyelectrodes 114 can be included on a single integrated patch andadhesively applied to the patient's body.

The sensing electrodes 112 can be configured to detect one or morecardiac signals. Examples of such signals include ECG signals, heartsounds, and/or other sensed cardiac physiological signals from thepatient. The sensing electrodes 112 can also be configured to detectother types of patient physiological parameters, such as tissue fluidlevels, lung sounds, respiration sounds, patient movement, etc. In someexamples, the therapy electrodes 114 can also be configured to includesensors configured to detect ECG signals as well as other physiologicalsignals of the patient. The connection pod 130 can, in some examples,include a signal processor configured to amplify, filter, and digitizethese cardiac signals prior to transmitting the cardiac signals to thecontroller 120. One or more therapy electrodes 114 can be configured todeliver one or more therapeutic defibrillating shocks to the body of thepatient 102 when the medical device 100 determines that such treatmentis warranted based on the signals detected by the sensing electrodes 112and processed by the controller 120.

As noted above, in some implementations, a gel deployment device caninclude conductive gel reservoirs that are configured to receive andstore a volume of conductive gel. The conductive gel reservoirs can beshaped or arranged on a substrate such that the reservoirs arepositioned substantially adjacent to at least one adhesive seal. Asdescribed herein, the conductive gel reservoirs can be configured tosurround one or more adhesive seals such that the conductive gelreservoir is about 0.5 mm from the adhesive seal. In certainimplementations, the conductive gel reservoirs can be positioned between0.25 mm and 1.5 mm from the adhesive seal in a substantially adjacentposition. As discussed in greater detail below, in some examples theconductive gel reservoirs can be shaped such that a single conductivegel reservoir surrounds a single adhesive seal. In such an example, whena pressurized fluid exerts a pressure on the conductive gel reservoir,the pressure exerted by the pressurized fluid can be subsequentlydistributed substantially equally about the perimeter of the adhesiveseal. Once the pressure exerted on the conductive gel reservoir reachesa predetermined pressure level configured to rupture the adhesive seal(e.g., in the range of 4-30 psi), the adhesive seal ruptures, therebyresulting in release of the conductive gel stored in the conductive gelreservoir. In certain implementations, the adhesive seals can beconfigured as frangible adhesive seals that are designed andmanufactured to rupture at a particular pressure level. For example, anexemplary adhesive seal can be configured to rupture at a predeterminedpressure level between 4-15 psi, or between 10-20 psi, or between 20-30psi, etc. The adhesive seal for a particular therapy electrodeapplication can be configured and selected to rupture at a particularpressure level by optimizing the size, shape and adhesive strength ofseal used to contain the conductive gel.

In some implementations, the adhesive seals can be configured to ruptureat a predetermined applied force. For example, the pressurized fluid canexert a force that is distributed substantially equally about theperimeter of the adhesive seal. Once the force exerted on a conductivegel reservoir reaches a predetermined force configured to rupture theadhesive seal (e.g., 5.5 N/cm²/sec to 15.2 N/cm²/sec), the adhesive sealruptures, thereby resulting in release of the conductive gel stored inthe conductive gel reservoir. Though the following description relatedto pressures exerted on the adhesive seals, it should be appreciatedthat the rupturing of the adhesive seals can be described by way ofexerted force as well.

In certain examples, the adhesive seal can rupture in a variety of ways.For example, a continuous portion of the adhesive seal (up to andincluding the full perimeter of the adhesive seal) can rupturesubstantially simultaneously, resulting in release of the conductive gelabout the full length of the continuous portion that has ruptured.Similarly, multiple points about the perimeter of the adhesive seal canrupture, thereby resulting in a fluid path for release of the conductivegel at each of the multiple rupture points.

An example of a single conductive gel reservoir surrounding a singleadhesive seal can be a substantially donut-shaped conductive gelreservoir. In such an example, the donut shape of the conductive gelreservoir defines an open center portion into which a ring-shapedadhesive seal can be placed. The geometry of such a design can result inany pressure applied to the ring-shaped adhesive seal (as a result of apressure being exerted on a conductive gel reservoir) being equallydistributed about the perimeter of the ring-shaped adhesive seal.Donut-shaped conductive gel reservoirs are described in greater detailbelow in the discussion of FIGS. 2A-2C.

In some implementations, multiple conductive gel reservoirs can bearranged in a reservoir cluster that surrounds a single adhesive seal.In such an implementation, rupturing of the single adhesive seal canresult in release of the conductive gel contained within each conductivegel reservoir in the reservoir cluster. In such an example, multipleconductive gel reservoirs can be arranged around a single adhesive sealsuch that a pressurized fluid applied to each of the conductive gelreservoirs can result in a pressure being exerted on multiple pointsabout the perimeter of the adhesive seal. As such, the exerted pressurecan be distributed about the adhesive seal until the pressure reachesthe predetermined pressure level configured to rupture the adhesiveseal. This provides the advantage of having more area for conductive gelflow through the ruptured adhesive seal as shown in FIGS. 3A-3D, whichare described in greater detail below. As before, the adhesive seal canrupture in a variety of ways. For example, a continuous portion of theadhesive seal (up to and including the full perimeter of the adhesiveseal) can rupture substantially simultaneously, resulting in release ofthe conductive gel about the full length of the continuous portion thathas ruptured. Similarly, one or multiple points about the perimeter ofthe adhesive seal can rupture, thereby resulting in a fluid path forrelease of the conductive gel at each of the multiple ruptured points.The adhesive seals, and how the adhesive seals rupture, are described ingreater detail below in the discussion of FIGS. 3A-3D.

An example of multiple conductive gel reservoirs associated with asingle adhesive seal can be a cluster of four conductive gel reservoirsarranged around a single ring-shaped adhesive seal. More or fewer suchconductive gel reservoirs can be employed in a single reservoir clusterwithout substantially deviating from the scope of this disclosure. Insome implementations, the arrangement of the conductive gel reservoirsinto a reservoir cluster can define an open center portion into which aring-shaped adhesive seal can be placed. The geometry of such a designcan result in any pressure being applied to the individual conductivegel reservoirs also being distributed about the perimeter of thering-shaped adhesive seal. For example, the exerted pressure can beapplied at multiple points about the perimeter of the ring-shapedadhesive seal or substantially continuously about the perimeter of theadhesive seal. Reservoir clusters including multiple conductive gelreservoirs are described in greater detail below in the discussion ofFIGS. 4A and 4B.

FIGS. 2A-2C illustrate a gel deployment device that, in combination witha conductive layer, can be used to manufacture or otherwise assemble atherapy electrode. This design includes a conductive gel deploymentdevice that uses a plurality of donut-shaped conductive gel reservoirson the conductive gel deployment device. This configuration places aring-shaped adhesive seal in the center of the donut-shaped conductivegel reservoir. Upon application of a pressurized fluid, pressure exertedby the pressurized fluid can be substantially equally distributed aboutthe entire circumference of the adhesive seal. After the pressurereaches the predetermined pressure level configured to rupture theadhesive seal, the adhesive seal can rupture resulting in a release ofthe conductive gel contained within the conductive gel reservoir.

FIG. 2A is a plan view of a therapy electrode 200 that includes aconductive gel deployment device 201 using, for example in thisconfiguration, donut-shaped conductive gel reservoirs 204. The therapyelectrode 200 can be a multiple layer laminated structure that includesa gel deployment device 201 and an electrically conductive layer 250(shown in FIG. 2C and explained in greater detail below). In use, theelectrically conductive layer 250 can be disposed proximate to thepatient's skin, although the conductive layer need not make directcontact with the patient (e.g., in implementations where conductiveportions of the garment 110 act as an interface between the conductivelayer 250 and the patient's skin, and/or implementations where portionsof the patient's clothing may be present between the electricallyconductive layer 250 and the patient's skin). In some implementations,the garment 110 can include a pocket or other similar structureincluding a metallic mesh that can be configured to act as an interfacebetween the electrically conductive layer 250 and the patient's skin. Inan example, the metallic mesh can include a knotted fabric having asilver coating. Upon deployment of the conductive gel, an electricalpathway can be defined between the electrically conductive layer 250 andthe patient's skin.

As shown in FIG. 2A, therapy electrode can include a substrate 202 aboutwhich various components of the gel deployment device 201 can bearranged. The substrate 202 can include a plurality of conductive gelreservoirs 204 distributed about the surface of the substrate 202. Forexample, the conductive gel reservoirs 204 can be disposed about a firstside of the substrate 202 (e.g., a top portion of the substrate 202 asdepicted in the plan view of FIG. 2A and positioned opposite a bottomportion or side of the therapy electrode 200 that includes, for example,the conductive layer 250). Each of the conductive gel reservoirs 204 canbe configured to hold a conductive gel. Depending upon the size of theconductive gel reservoirs, and the number of conductive gel reservoirsused, the amount of conductive gel contained within each conductive gelreservoir can be adjusted accordingly. For example, a gel deploymentdevice 201 can include approximately 3-20 ml of conductive gel. In otherexamples, the gel deployment device 201 can be configured to holdbetween 5-15 ml of conductive gel. The conductive gel can be distributedamongst each of the conductive gel reservoirs 204. For example, eachconductive gel reservoir 204 can be configured to hold approximately0.5-5.0 ml of conductive gel. In other examples, each conductive gelreservoir can be configured to hold between 1.0 and 4.0 ml of conductivegel. In come implementations, depending upon the number and shape of theconductive gel reservoirs 204, additional quantities of conductive gelcan be included in each conductive gel reservoir 204. For example, eachconductive gel reservoir 204 can be configured to hold 6 ml ofconductive gel, 7 ml of conductive gel, 8 ml of conductive gel, 9 ml ofconductive gel, or 10 ml of conductive gel. As such, by varying theamount of total conductive gel held within each conductive gel reservoir204, the total amount of gel contained within gel deployment device 201can be adjusted.

In certain embodiments, the amount of conductive gel in each of theconductive gel reservoirs 204 can be equal or substantially equal suchthat the total amount of conductive gel is distributed among each of theconductive gel reservoirs 204. In other examples, the amount ofconductive gel in each of the conductive gel reservoirs 204 can vary.

In certain implementations, gel deployment device 201 can includeapproximately 10 ml of conductive gel distributed substantially equallyamong each of the conductive gel reservoirs 204. As shown in the examplegel deployment device 201 illustrated in FIG. 2A, with ten conductivegel reservoirs 204, each conductive gel reservoir 204 can be configuredto hold approximately 0.5-1.5 ml of conductive gel. In some examples,each conductive gel reservoir 204 can be configured to holdapproximately 1.0 ml of conductive gel. As noted above, in otherexamples, gel deployment device 201 can be configured to hold betweenapproximately 3 ml and 20 ml of conductive gel. In such an example, eachconductive gel reservoir 204 can be configured to hold approximately0.3-2.0 ml of conductive gel. The amount of conductive gel can bedetermined based upon the number of reservoirs being used as well as thesize of the electrically conductive layer the conductive gel isconfigured to be deployed on. For example, to provide an adequate amountof gel prior to delivering a therapeutic shock, a certain volume of gelper surface area of the therapy electrode can be delivered. In someexamples, a ratio of between 0.3 and 2 ml of conductive gel per squareinch of therapy electrode surface area can be used. In certainembodiments, a ratio of 1 ml per square inch of surface area can beused. As such, for a therapy electrode having a surface area ofapproximately 10 square inches, a gel deployment device can include 10ml of conductive gel. In some implementations, the amount of conductivegel in the gel deployment device can also be based upon properties ofthe conductive gel itself. If the conductive gel has a low viscosity(e.g., a viscosity of about 100 mPa·s), a lower amount of the conductivegel can be used (e.g., .75 ml per square inch of surface area) as theconductive gel is more likely to flow along the surface of the therapyelectrode as a faster pace than with a higher viscosity. Conversely, ifthe conductive gel has a higher viscosity (e.g., a viscosity of about500 mPa·s), a larger amount of conductive gel can be used (e.g., 1.25 mlper square inch of surface area) as the conductive gel is more likely toflow along the surface of the therapy electrode at a slower pace.

Additionally, the therapy electrode 200 can also include a set ofconductive gel reservoir protective caps 205. The protective caps 205can be configured to cover the conductive gel reservoirs 204 to provideprotection. In certain implementations, the protective caps 205 can bemade from a hard plastic such as polystyrene or polycarbonate. Theprotective caps 205 can be sized (e.g., have a preconfigured thickness)such that the protective caps 205 provide a rigid outer structure forabsorbing any accidental force or pressure exerted on the outside of theconductive gel reservoirs 204 prior to release of the conductive gelcontained therein. In certain configurations, each of the conductive gelreservoirs 204 can have a single protective cap 205. In otherimplementations, the protective caps 205 can be sized to protectmultiple conductive gel reservoirs 204.

As shown in FIG. 2B, each of the conductive gel reservoirs 204 can alsobe positioned around an adhesive seal 210, such as a ring-shapedadhesive seal. The adhesive seal 210 can be positioned such that it canprevent release of the conductive gel to a gel delivery outlet or exitport 212.

Referring again to FIG. 2A, the therapy electrode 200 can furtherinclude a pressure source 206 connected to a fluid channel 208. Examplesof various pressure sources can be found in, for example, U.S. patentapplication Ser. No. 15/072,590 filed Mar. 17, 2016 and entitled“Systems and Methods for Conductive Gel Deployment,” the content ofwhich is incorporated herein by reference in its entirety. A copy ofU.S. patent application Ser. No. 15/072,590 is included herein asAppendix A.

The pressure source 206, when activated by an activation signal, canrelease a pressurized fluid, such as a compressed gas, into the fluidchannel 208. The fluid channel 208 can include a foam such as melaminefoam positioned and configured to define a fluid passage between thepressure source 206 and each of the conductive gel reservoirs 204.

The hydraulic pressure of the fluid from the activated fluid pressuresource 206 in the fluid channel 208 can result in a pressure beingexerted on each of the conductive gel reservoirs 204. The pressureexerted on each of the conductive gel reservoirs 204 can result in theeventual rupturing of each adhesive seal 210 at or about substantiallyat the predetermined pressure level configured to rupture the adhesiveseal. More specifically, as a result of the shape of the conductive gelreservoirs 204, the pressure exerted by the pressure source 206 can forma distributed pressure about the perimeter of the adhesive seal 210.Thus, the adhesive seal 210 can be more likely to rupture at multiplepoints about the perimeter (or rupture in a continuous portion up to andincluding the full perimeter of the adhesive seal) at or aboutsubstantially at the predetermined pressure level configured to rupturethe adhesive seal 210, thereby resulting in release of the conductivegel from the conductive gel reservoirs 204. Such a configuration canoffer an advantage over a configuration involving an adhesive sealconfigured to rupture from pressure being applied at only a singlepoint. For instance, multiple points of applied pressure to the adhesiveseal 210 can improve a likelihood that the adhesive seal 210 will besubjected to pressures at or about the predetermined pressure level,thereby increasing the likelihood that each of the multiple points ofapplied pressure will rupture, providing more area for the conductivegel to flow out of the conductive gel reservoirs 204.

Upon release of the adhesive seal 210, the conductive gel stored in eachof the plurality of conductive gel reservoirs 204 can flow out of theplurality of exit ports 212, through apertures formed in theelectrically conductive layer, and onto the exposed surface of theelectrically conductive layer proximate to the patient's skin. Theapertures in the electrically conductive layer are configured to besubstantially aligned with the plurality of exit ports 212 so that, whenreleased, the electrically conductive gel is dispensed onto the exposedsurface of the electrode portion that is disposed substantiallyproximate to the patient's body (e.g., the electrically conductive layer250). In some implementations, the apertures in the electricallyconductive layer can be offset from the plurality of exit ports 212,depending upon the shape and size of the conductive gel reservoirs 204and the adhesive seals 210. Such a design can provide an advantageduring assembly of the therapy electrode 200 as manufacturing tolerancescan be increased as a result of the potential offset of the aperturesand the exit ports 212.

FIG. 2B shows a cross-sectional view of a single donut-shaped conductivegel reservoir 204. As shown in FIG. 2B, each individual conductive gelreservoir 204 can have a donut-shape that defines an open center portion214. As noted above, the adhesive seal 210 can be positioned in thecenter of the conductive gel reservoir 204 within the open centerportion 214. Similarly, an exit port 212 can be positioned in the centerof the adhesive seal 210. In certain implementations, upon release ofthe adhesive seal 210, the conductive gel contained within theconductive gel reservoir 204 can flow through the exit port 212.Additional detail related to the operation of therapy electrode 200 isprovided below.

FIG. 2C illustrates an exploded view of the therapy electrode 200,showing the multiple layers included in the manufacturing process of thetherapy electrode 200. In certain implementations, a set of layers asshown in FIG. 2C (e.g., layers 220, 230 and 240 as described in greaterdetail below) can be assembled to manufacture the gel deployment device201. It should be noted that the details provided in FIG. 2C andexplained herein, as well as the overall process discussed below, isprovided by way of example only. For example, changes to the techniquesand configurations described herein can be implemented withoutsubstantially deviating from the scope of the disclosure.

The multilayer assembly as shown in FIG. 2C can include an outer layer220. The outer layer 220 can be formed from, for example, variouspolymers such as formed thermoplastic. In some implementations, theouter layer 220 can be constructed from an ethylene acid copolymer. Insome examples, a copolymer having a low water vapor transmission ratecan be chosen. For example, the outer layer 220 can be constructed fromDuPont™ Surlyn®, which is an ionomer resin of ethylene acid copolymer.Such a resin can be processed in conventional blown film, cast film,sheet extrusion and coextrusion equipment designed to processpolyethylene and ethylene copolymer type resins. The ionomer resin canbe configured to have a relatively low water vapor transmission rate(e.g., approximately 0.8 g/100 in²/day). For example, a material with alow permeability such as an ionomer resin can provide an advantage of alonger shelf-life of the conductive gel deployment device relative toconventional configurations as the rate of evaporation of the conductivegel through the ionomer resin is low. Thus, the conductive gel insidethe conductive gel reservoirs (e.g., conductive gel reservoirs 204) canmaintain its original viscosity when stored in the conductive gelreservoirs for an extended period of time (e.g., for a period of two ormore years).

In some examples, the outer layer 220 can be manufactured from theionomer resin using a vacuum forming machine. An appropriately sizedsheet of the ionomer resin can be placed into the vacuum forming machinealong with a mold or plate including a negative of the features to beformed on the outer layer 220. The sheet of the ionomer resin can beappropriately heated, stretched against the mold, and pressed againstthe mold by a vacuum pressure. After the pressure is released, the sheetof ionomer resin has been molded into the outer layer 220. Based uponthe resulting desired characteristics of the outer layer 220, thephysical properties of the ionomer resin sheet can be chosen or adjustedaccordingly. For example, the thickness of the ionomer resin sheet canbe selected based upon the desired flexibility of the finished outerlayer 220 as well as the pressures that will be exerted on the outerlayer 220. In some examples, the thickness of the ionomer resin sheetcan be between 0.0095-0.0120 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.011 inches thick.Additional characteristics such as resin density and other relatedproperties can also be determined based upon resulting desiredcharacteristics of the finished outer layer 220.

The outer layer 220 can include multiple gel reservoir top portions 222.The gel reservoir top portions 222 can be formed to provide an airpocket as well as to provide a surface against which a pressurized fluidcan exert a pressure when applied to a conductive gel reservoir 204.Similarly, the outer layer 220 can include a pressure source top portion224. The pressure source top portion 224 can be arranged to define acavity for insertion and containment of, for example, pressure source206.

Additionally, the outer layer 220 can include one or more ventilationholes 226. When worn by a patient, the therapy electrode 200 issubstantially held against the patient's skin (or, depending upon thetype of garment 110 being worn, a layer of the garment 110 can bepositioned between the therapy electrode 200 and the patient's skin). Byincluding the ventilation holes 226 (in combination with ventilationholes 234, 242 and 254 described below in additional detail), increasedair flow can be provided to a patient's skin, thereby reducing potentialdiscomfort or skin irritation.

The multilayer assembly as shown in FIG. 2C can also include a diaphragmlayer 230. Like the outer layer 220, the diaphragm layer 230 can beformed from, for example, an ionomer resin. As before, a vacuum formingprocess can be used to form a sheet of the ionomer resin into thediaphragm layer 230. An appropriately sized sheet of the ionomer resincan be placed into the vacuum forming machine along with a mold or plateincluding a negative of the features to be formed on the diaphragm layer230. The sheet of the ionomer resin can be appropriately heated,stretched against the mold, and pressed against the mold by a vacuumpressure. After the pressure is released, the sheet of ionomer resin hasbeen molded into the diaphragm layer 230. Based upon the resultingdesired characteristics of the diaphragm layer 230, the physicalproperties of the ionomer resin sheet can be chosen or adjustedaccordingly. For example, the thickness of the ionomer resin sheet canbe selected based upon the desired flexibility of the finished diaphragmlayer 230. In some examples, the thickness of the ionomer resin sheetcan be between 0.0095-0.0120 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.011 inches thick.Additional characteristics such as resin density and other relatedproperties can also be determined based upon resulting desiredcharacteristics of the finished diaphragm layer 230.

The diaphragm layer 230 can also include multiple gel reservoir innerportions 232. The gel reservoir inner portions 232 can be formed suchthat, upon layering of the outer layer 220 and the diaphragm layer 230,a small air gap is defined between each gel reservoir top portion 222and a corresponding gel reservoir inner portion 232. As such, the gelreservoir inner portions 232 can be sized slightly smaller than the gelreservoir top portions 222. This size difference allows the smaller gelreservoir inner portions 232 to nest within the gel reservoir topportions 222 and define the air gap there-between. With such anarrangement of components, upon application of an exerted pressure froma pressurized fluid, pressure within the air gap can increase until anadjacent adhesive seal ruptures. When the adhesive seal ruptures, theexerted pressure can deform the gel reservoir inner portion 232, therebycausing flow of the conductive gel contained within that conductive gelreservoir 204. Additionally, the second layer 230 can include one ormore ventilation holes 234 in alignment with ventilation holes 226.

The multilayer assembly as shown in FIG. 2C can further include alidding layer 240. The lidding layer 240 is configured to adhere to thediaphragm layer 230 to provide a sealing surface for holding theconductive gel within gel reservoir inner portions 232 of the diaphragmlayer 230. The lidding layer 240 can be formed from, for example, apolyester film that includes a heat sealable adhesive layer. In someexamples, Scotchpak™ MA250M Medical Adhesion Film can be used for theconstruction of the lidding layer 240. Similar to the ionomer resinsheet as described above, the thickness of the polyester film can beselected based upon the desired flexibility of the finished liddinglayer 240. In some examples, the thickness of the ionomer resin sheetcan be between 0.00230-0.00260 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.00245 inches thick.Additionally, like the ionomer resin as described above, a polyesterfilm with a low permeability and water vapor transmission rate can beselected. Additional characteristics such as adhesive density and otherrelated properties can also be determined based upon resulting desiredcharacteristics of the finished lidding layer 240.

As described above, the lidding layer 240 can be configured to act asbarrier layer preventing unwanted release of the conductive gel from theconductive gel reservoirs 204. As such, the adhesive seals 210 can beconfigured and positioned between the diaphragm layer 230 and thelidding layer 240. Additional detail regarding adhesive seals, and theirincorporation and positioning in a gel deployment device, is provided inthe discussion of FIGS. 3A-3D provided below.

Similarly, the lidding layer 240 includes exit ports 212 (as shown inFIG. 2B) positioned adjacent to (or, if a ring-shaped adhesive seal isused, in the center of) the adhesive seals 210. Additionally, thelidding layer 240 can include one or more ventilation holes 242 inalignment with ventilation holes 226 and ventilation holes 234 asdescribed above.

When manufactured, the outer layer 220, the diaphragm layer 230 and thelidding layer 240 can be combined into a multilayer gel deploymentdevice 201. As noted above, the gel deployment device 201 can beconfigured to deploy an amount of conductive gel prior to applicationof, for example, a therapeutic shock.

As noted above, a therapy electrode 200 can also include an electricallyconductive layer 250. The electrically conductive layer 250 can beformed from a conductive material such as metal foil or another thin,pliable conductive material. For example, the electrically conductivelayer 250 can be constructed from rolled stainless steel. In someexamples, the thickness of the electrically conductive layer 250 can bebetween 0.00295-0.00305 inches thick. In certain implementations, thethickness of the electrically conductive layer 250 can be approximately0.003 inches thick.

The electrically conductive layer 250 can be configured to be positionedsubstantially proximate to the patient's skin and to direct atherapeutic shock towards the patient's skin. Depending upon the design,the electrically conductive layer 250 can also be integrated directlyinto the garment, e.g., garment 110 as described above. In certainimplementations, the electrically conductive layer 250 is positioned andconfigured to work in concert with gel deployment device 201. Thisprovides for a replaceable gel deployment device 201 that can bereplaced without replacing the electrically conductive layer 250 aswell. An example of a garment including an integrated electricallyconductive layer and a replaceable gel deployment device is described indetail in U.S. Pat. No. 9,008,801 issued Apr. 14, 2015 and entitled“Wearable Therapeutic Device,” the content of which is incorporatedherein by reference.

Additionally, the electrically conductive layer 250 can include a seriesof apertures 252. The apertures 252 can be arranged in a similargeometry as the placement of the adhesive seals 210 and the exit ports212 (as shown, for example, in FIG. 2B). Such an arrangement ofcomponents provides for conductive gel flow through the exit ports 212and then through the apertures 252 in the electrically conductive layer250 and onto a patient's skin.

When applying a therapeutic shock, the electrical current typicallymoves to the edges of the conductive material prior to arcing to thepatient's skin. When the current collects at the edge prior to arcing tothe patient's skin, more current is applied to a single area of thepatient's skin, which can result in tissue damage to the patient's skin(e.g., a burn or other similar skin irritation). In order to betterbalance the electrical current delivered to the patient (e.g., to allowfor substantially even distribution of the current through theelectrode-patient interface), the electrically conductive layer 250 caninclude one or more openings, e.g., opening 254. For example, theopening 254 can define an additional edge for better distributing theelectrical current. Thus, as shown in FIG. 2C, the electricallyconductive layer 250 includes an outer edge 256 designed by the overallshape of the therapy electrode, as well as an inner edge 258 defined bythe opening 254. The combination of both the outer edge 256 and theinner edge 258 combine to increase an overall edge length of theelectrically conductive layer 250. In some examples, the opening 254 canbe configured to substantially align with at least a portion of theventilation holes 226, ventilation holes 234, and ventilation holes 242to facilitate air flow to the patient's skin adjacent to the therapyelectrode 200. However, other configurations are possible, includingventilation holes 226, 234 and 242 being disposed at locations otherthan in alignment with the opening 254.

By providing ventilation to the patient's skin (e.g., via thecombination of ventilation holes 226, 234, 242 and the opening 254), thetherapy electrode 200 can provide several advantages over conventionaldesigns. For example, increased air flow can reduce the likelihood thata patient will experience discomfort due to sweating as a result of thetherapy electrode 200 being pressed against their skin. The increasedairflow can cool the skin covered by the therapy electrode 200 as wellas facilitate evaporation of any sweat that is produced by the skincovered by the therapy electrode 200.

The electrically conductive layer 250 as shown in FIG. 2C is shown byway of example only. As noted above, by increasing the total edge lengthof the electrically conductive layer 250, the electrical current can bemore evenly distributed to the patient. As such, the electricallyconductive layer 250 can include additional holes having preconfiguredshapes (e.g., a star, a flower, a diamond, or any arbitrary shape) toincrease the total edge length. Similarly, the outer edge 256 caninclude a preconfigured design such as a scalloped edge or anyarbitrarily shaped edge rather than being, for example, cut straight,thereby also increasing the total edge length.

Similarly, it should be noted that the number, shape, and position ofthe ventilation holes 226, 234 and 242 are shown by way of example only.Depending upon the layout of the conductive gel reservoirs 204, thenumber, shape, and position of the ventilation holes can be alteredaccordingly.

As noted above, each of the lidding layer 240 and the electricallyconductive layer 250 includes one or more exit ports in the liddinglayer 240 (e.g., exit ports 212 as shown in FIG. 2B) and apertures 252in the electrically conductive layer 250 positioned such that the exitports and apertures 252 are aligned with the open center portion (e.g.,open center portion 214 as shown in FIG. 2B) of each conductive gelreservoir 204. Depending upon the manufacturing process, the exit ports212 and apertures 252 can be formed in the lidding layer 240 and theelectrically conductive layer 250 prior to or during assembly of themultilayer device illustrated in FIG. 2C. In traditional manufacturingprocesses, the adhesive seals are positioned adjacent to the conductivegel reservoirs during an assembly process. However, this step canrequire precise position of the therapy electrode to properly positionthe adhesive seals with the conductive gel reservoirs. Using the designsand techniques as described herein, for example, the open center portion214 of the conductive gel reservoirs can be used to align a piercingdevice configured to pierce the multilayered device to produce the exitports 212 and the apertures 252 during manufacture, thereby increasingthe manufacturing tolerances of the therapy electrode 200 as thepiercing device can be configured to adjust to the positions of the opencenter portions 214. However, if such a process is used, for example, tostamp out the exit ports 212 and the apertures 252 after assembly of themultilayered assembly, a sealant or adhesive plug (not shown in FIG. 2C)can be applied to the outer layer 220 to prevent unwanted fluid flowupon release of the conductive gel.

In an example manufacturing process, each layer as shown in FIG. 2C canbe configured to be adhered to its adjacent layers via an adhesionprocess. For example, each of the outer layer 220 and the diaphragmlayer 230 can be bonded together directly. Heat and pressure can beapplied to each of the outer layer 220 and the diaphragm layer 230 to,e.g., chemically bond the two layers together. As noted above, thelidding layer 240 can be manufactured from a polyester film thatincludes a heat-activated adhesive. In certain implementations, thediaphragm layer 230 (or the combined top layer 220 and diaphragm layer230) can be positioned on top of the lidding layer 240 such that thelidding layer 240 acts to seal the conductive gel in the gel reservoirinner portions 232 of the diaphragm layer 230. Heat can be applied tothe stacked structure, thereby forming the multilayer gel deploymentdevice as described above. Additionally, an amount of heat-activatedadhesive (or another similar adhesive) can be applied between thelidding layer 240 and the electrically conductive layer 250. Theelectrically conductive layer 250 can then be adhered to the liddinglayer 240 (and, subsequently, the multilayered gel deployment device),thereby resulting in a complete therapy electrode 200.

In operation, the therapy electrode 200 as describe above can beconfigured to provide a therapeutic shock to a patient currentexperiencing, for example, a cardiac arrhythmia. Prior to delivering theshock, the conductive gel deployment device 201 associated with thetherapy electrode 200 can be configured to deploy the conductive gelonto the patient's skin. Initially, the pressure source 206 can betriggered to produce an increased fluid pressure in the fluid channel208. The increased fluid pressure can cause internal pressure within theair gaps between each gel reservoir top portion 222 and its adjacent gelreservoir inner portion 232 to increase. As the internal pressure withinthe conductive gel reservoirs 204 increases, a distributed pressure canbe applied about the perimeter of each of the adhesive seals 210. Afterthe distributed pressure reaches a high enough level (e.g., 8-22 psi),each individual adhesive seal 210 can begin to rupture, causing therelease of the conductive gel from each of the conductive gel reservoirs204. Pressure within each of the conductive gel reservoirs 204 can causedeformation of the gel reservoir inner portion 232, which results in theconductive gel being pushed out of the conductive gel reservoirs 204.The conductive gel can flow through the exit ports 212 and can bedistributed on the electrically conductive surface 250 and the patient'sskin. After gel deployment, the electrically conductive surface 250 candirect the therapeutic shock through the conductive gel, which conductsthe therapeutic shock to the patient's skin.

FIGS. 3A-3D illustrate a detailed view of a conductive gel reservoir andan adhesive seal, as well as provide additional detail regarding how anadhesive seal ruptures and the resulting conductive gel flow through theruptured adhesive seal to an exit port. FIG. 3A shows a close-up view ofconductive gel reservoir 300. In certain embodiments, the conductive gelreservoir 300 can have, for example a donut shape. Similar to thediscussion of FIG. 2B above, the conductive gel reservoir can surroundan adhesive seal 302. The adhesive seal 302 can be positioned andconfigured such that it prevents flow of conductive gel from theconductive gel reservoir 300 to an exit port 304.

The adhesive seal 302 can be positioned or inserted between thediaphragm layer and the lidding layer. FIG. 3B shows a cross-sectionalview of a portion of a gel deployment device. In particular, FIG. 3Bshows the diaphragm layer 310 and the lidding layer 312. As describedabove, in order to adhere the diaphragm layer 310 and the lidding layer312, a certain amount of heat can be applied to the two layers. Thediaphragm layer 310 and the lidding layer 312 can then be pressedtogether using a certain force. By altering the temperature and theforce, the peeling strength of the assembled layers (e.g., a pressurelevel at which the diaphragm layer 310 and the lidding layer 312 willpull apart) can be configured for an intended purpose. For example, tosecurely fasten the lidding layer 312 to the diaphragm layer 310 forprevention of conductive gel leakage from the conductive gel reservoirs300, the layers can be bonded at area 314 at approximately 300° F. witha pressing force of approximately 10 N for about 3 seconds. Such abonding can have, for example, a peeling strength of 100 psi.

In certain embodiments, the adhesive seal 302 can be formed to have alower peeling strength than area 314. For example, in order to cause theadhesive seal 302 to rupture in response to an applied pressure ofapproximately 8-22 psi (as described above), the adhesive seal 302 canbe configured to have a peeling strength of approximately 10 psi. Toform such an adhesive seal 302, a lower temperature and force can beused when forming the adhesive seal 302 between the diaphragm layer 310and the lidding layer 312. For example, the diaphragm layer 310 and thelidding layer 312 can be bonded at approximately 300° F. with a pressingforce of approximately 7.5 N for about 3 seconds to form the adhesiveseal 302. By providing a lower peeling strength for the adhesive seal302 relative to layer bonding area 314, the adhesive seal 302 isconfigured to rupture at a lower pressure (e.g., 8-22 psi), therebyfacilitating release of the conductive gel from the conductive gelreservoir 300 to the exit port 304. Additionally, the thickness (e.g.,the difference between the outer diameter minus the inner diameter) ofthe adhesive seal 302 can be configured to provide a particular peelingstrength. For example, the adhesive seal 302 can have a thickness ofapproximately 0.0005-0.004 inches thick. In certain implementations, theadhesive seal 302 can have a thickness of approximately 0.001 inchesthick.

As described herein, the adhesive seal 302 is thus a particular area ofadhesion between the diaphragm layer 310 and the lidding layer 312 thathas a configured peeling strength. However, such an adhesive seal 302 isprovided by way of example only. In certain embodiments, the seal 302can include an additional component inserted between the diaphragm layer310 and the lidding layer 312. For example, the seal 302 can include arubber (or other similar material such as a flexible foam) O-ringpositioned between the diaphragm layer 310 and the lidding layer 312 andsecured (e.g., via a rubber adhesive) between the diaphragm layer 310and the lidding layer 312 to provide a configured peeling strengthbetween the layers.

FIGS. 3C and 3D illustrate an example of applied pressure to an adhesiveseal (FIG. 3C) and a ruptured adhesive seal and resulting conductive gelflow (FIG. 3D). As shown in FIG. 3C, when a pressure (e.g., from apressurized fluid) is applied to a conductive gel reservoir, thepressure is evenly or substantially even distributed about the perimeterof the adhesive seal, as is indicated by the arrows in FIG. 3C. Itshould be noted that, though the arrows in FIG. 3C indicate pressurebeing applied at a number of points about the adhesive seal, this isprovided by way of example only and, in actual practice, the pressure isapplied evenly or substantially evenly about the perimeter of theadhesive seal. As the applied pressure reaches a level that results inrupturing of the adhesive seal (e.g., 8-22 psi as described above), theadhesive seal can rupture at one or more points about the perimeter ofthe adhesive seal. For example, a continuous portion of the adhesiveseal (up to an including the full perimeter of the adhesive seal) canrupture substantially simultaneously, resulting in release of theconductive gel about the full length of the continuous portion that hasruptured. Similarly, multiple points about the perimeter of the adhesiveseal can rupture, thereby resulting in a fluid path for release of theconductive gel at each of the multiple rupture points.

As shown in FIG. 3D, for example, various portions of the adhesive sealhave failed. As indicated by the arrows in FIG. 3D, the conductive fluidcan flow through the ruptured portions of the adhesive seal and to theexit port. As noted above, the pressure applied to the conductive gelreservoir (that resulting in the rupturing of the adhesive seal) alsoacts to push the conductive gel out of the conductive gel reservoir,through the ruptured portions of the adhesive seal and to the exit port.It should be noted that, though the arrows in FIG. 3D indicate a limitednumber of conductive gel paths for flowing through the ruptured adhesiveseal, this is provided by way of example only and, in actual practice,the conductive gel would flow from the conductive gel reservoir to theexit port through any portion of the adhesive seal that has ruptured ata rate determined by the pressure applied to the conductive gelreservoir.

FIGS. 4A and 4B illustrate a conductive gel deployment device that usesreservoir clusters on the conductive gel deployment device. Thisconfiguration places a ring-shaped adhesive seal in the center of acluster of individual conductive gel reservoirs such that multipleconductive gel reservoirs can be arranged about a single adhesive seal.Upon application of a pressure to the conductive gel reservoirs, adistributed pressure is exerted about a perimeter of the adhesive seals.In such an example, the adhesive seal can rupture in a variety of ways.For example, a continuous portion of the adhesive seal (up to anincluding the full perimeter of the adhesive seal) can rupturesubstantially simultaneously, resulting in release of the conductive gelabout the full length of the continuous portion that has ruptured.Similarly, multiple points about the perimeter of the adhesive seal canrupture, thereby resulting in a fluid path for release of the conductivegel at each of the multiple rupture points.

FIG. 4A is a plan view of a therapy electrode 400 that includes aconductive gel deployment device 401 using, for example in thisconfiguration, reservoirs clusters. Like therapy electrode 200, thetherapy electrode 400 can be a multiple layer laminated structure thatincludes an electrically conductive layer 450 (shown in FIG. 4B andexplained in greater detail below). In use, the electrically conductivelayer 450 can be disposed proximate to the patient's skin, although theconductive layer need not make direct contact with the patient (e.g., inimplementations where conductive portions of the garment 110 act as aninterface between the conductive layer 450 and the patient's skin,and/or implementations where portions of the patient's clothing may bepresent between the electrically conductive layer 450 and the patient'sskin). In some implementations, the garment 110 can include a pocket orother similar structure including a metallic mesh that can be configuredto act as an interface between the electrically conductive layer 450 andthe patient's skin. In an example, the metallic mesh can include aknotted fabric having a silver coating. Upon deployment of theconductive gel, an electrical pathway can be defined between theelectrically conductive layer 450 and the patient's skin.

As shown in FIG. 4A, therapy electrode can include a substrate 402 aboutwhich various components of the gel deployment device 401 can bearranged. The substrate 402 can include a plurality of reservoirclusters 403 distributed about the surface of the substrate 402. Each ofthe reservoir clusters 403 can include multiple conductive gelreservoirs 404. For example, as shown in FIG. 4A, each conductive gelcluster 403 includes four conductive gel reservoirs 404 arranged about acenter point, thereby defining an open center position. In certainimplementations, the gel clusters 403 can be disposed about a first sideof the substrate 402 (e.g., a top portion of the substrate 402 asdepicted in the plan view of FIG. 4A and positioned opposite a bottomportion or side of the therapy electrode 400 that includes, for example,the conductive layer 450). Each of the conductive gel reservoirs 404 canbe configured to hold a volume of conductive gel. Depending upon thetotal number of conductive gel reservoirs 404 used for each reservoircluster 403, and the total number of reservoir clusters 403 used, theamount of conductive gel contained within each conductive gel reservoir404 can be adjusted accordingly. For example, the gel deployment device401 can include approximately 3-20 ml of conductive gel. In otherexamples, the gel deployment device 401 can be configured to holdbetween 5-15 ml of conductive gel. The conductive gel can be distributedamongst each of the conductive gel reservoirs 404. For example, eachconductive gel reservoir 404 can be configured to hold approximately0.5-5.0 ml of conductive gel. In other examples, each conductive gelreservoir 404 can be configured to hold between 1.0 and 4.0 ml ofconductive gel. In come implementations, depending upon the number andshape of the conductive gel reservoirs 404, additional quantities ofconductive gel can be included in each conductive gel reservoir 404. Forexample, each conductive gel reservoir 404 can be configured to hold 6ml of conductive gel, 7 ml of conductive gel, 8 ml of conductive gel, 9ml of conductive gel, or 10 ml of conductive gel. As such, by varyingthe amount of total conductive gel held within each conductive gelreservoir 404, the total amount of gel contained within gel deploymentdevice 401 can be adjusted.

In certain embodiments, the amount of conductive gel in each of theconductive gel reservoirs 404 can be equal or substantially equal suchthat the total amount of conductive gel is distributed among each of theconductive gel reservoirs 404. In other examples, the amount ofconductive gel in each of the conductive gel reservoirs 404 can vary.

In certain implementations, the gel deployment device 401 can beconfigured to hold approximately 10 ml of the conductive gel distributedsubstantially equally among each of the conductive gel reservoirs 404.As shown in the example gel deployment device illustrated in FIG. 4A,with twelve conductive gel reservoirs 404, each conductive gel reservoir404 can be configured to hold approximately 0.85 ml of conductive gel.As noted above, in other examples, a gel deployment device can beconfigured to hold between approximately 3 ml and 20 ml of conductivegel. The amount of conductive gel can be determined based upon thenumber of reservoirs being used as well as the size of the electricallyconductive layer the conductive gel is configured to be deployed on. Incertain embodiments, the amount of conductive gel in each of theconductive gel reservoirs can be equal or substantially equal such thatthe total amount of conductive gel is distributed among each of theconductive gel reservoirs.

Additionally, the therapy electrode 400 can also include a set ofconductive gel reservoir protective caps 405. The protective caps 405can be configured to cover the conductive gel reservoirs 404 to provideprotection. In certain implementations, the protective caps 405 can bemade from a hard plastic such as polystyrene or polycarbonate. Theprotective caps 405 can be sized (e.g., have a preconfigured thickness)such that the protective caps 405 provide a rigid outer structure forabsorbing any accidental force or pressure exerted on the outside of theconductive gel reservoirs 404 prior to release of the conductive gelcontained therein. In certain configurations, each of the conductive gelreservoirs 404 can have a single protective cap 405. In otherimplementations, the protective caps 405 can be sized to protectmultiple conductive gel reservoirs 404. For example, a single protectivecap 405 can be sized to cover a reservoir cluster 403.

Each of the reservoir clusters 403 can be positioned around an adhesiveseal 410, such as a ring-shaped adhesive seal. The adhesive seal 410 canbe positioned such that it can prevent release of the conductive gel toa gel delivery outlet or exit port 412.

The therapy electrode 400 can further include a pressure source 406connected to a fluid channel 408. The pressure source 406, whenactivated by an activation signal, can release a fluid, such ascompressed gas, into the fluid channel 408. The fluid channel 408 caninclude a foam such as melamine foam positioned and configured to definea fluid passageway between the pressure source 406 and each of theconductive gel reservoirs 404.

The hydraulic pressure of the fluid from the activated fluid pressuresource 406 in the fluid channel 408 can result in a pressure beingexerted on each of the conductive gel reservoirs 404. The pressureexerted on each of the conductive gel reservoirs 404 can result in theeventual rupturing of each adhesive seal 410 at or about substantiallyat the predetermined pressure level configured to rupture the adhesiveseal 410. In certain implementations, as a result of the shape of theconductive gel reservoirs 404 and their positioning within the reservoircluster 403, the pressure exerted by the pressure source 406 can form adistributed pressure about the perimeter of the adhesive seal 410. Thus,the adhesive seal 410 can be more likely to rupture at multiple pointsabout the perimeter (or in a continuous portion up to and including thefull perimeter of the adhesive seal 410), at or about substantially atthe predetermined pressure level configured to rupture the adhesive seal410, thereby resulting in release of the conductive gel from eachreservoir cluster 403. Such a configuration can offer an advantage overa configuration involving an adhesive seal configured to rupture frompressure being applied at only a single point. For instance, multiplepoints of applied pressure to the adhesive seal 410 can improve alikelihood that the adhesive seal 410 will be subjected to pressures ator about the predetermined pressure level, thereby increasing thelikelihood that each of the multiple points of applied pressure willrupture, providing more area for the conductive gel to flow out of theconductive gel reservoirs 404.

Upon release of the adhesive seal 410, the conductive gel stored in eachof the plurality of conductive gel reservoirs 404 in a respectivereservoir cluster 403 can flow out of the plurality of exit ports 412.The conductive gel then can flow through apertures formed in theelectrically conductive layer 450 and onto the exposed surface of theelectrically conductive layer 450 proximate to the patient's skin. Theapertures in the electrically conductive layer 450 are configured to besubstantially aligned with the plurality of exit ports 412 so that, whenreleased, the electrically conductive gel is dispensed onto the exposedsurface of the electrode portion that is disposed substantiallyproximate to the patient's body. In some implementations, the aperturesin the electrically conductive layer can be offset from the plurality ofexit ports 412, depending upon the shape and size of the conductive gelreservoirs 404, the arrangement of the reservoir clusters 403, and theadjacent adhesive seals 410. Such a design can provide an advantageduring assembly of the therapy electrode 400 as manufacturing tolerancescan be increased as a result of the potential offset of the aperturesand the exit ports.

FIG. 4B illustrates an exploded view of the therapy electrode 400,showing the multiple layers included in the manufacturing process of thetherapy electrode 400. In certain implementations, a set of layers asshown in FIG. 4B (e.g., layers 420, 430 and 440 as described in greaterdetail below) can be assembled to manufacture the gel deployment device401. It should be noted that the details provided in FIG. 4B andexplained herein, as well as the overall process discussed below, isprovided by way of example only. For example, changes to the techniquesand configurations described herein can be implemented withoutsubstantially deviating from the scope of the disclosure.

The multilayer assembly as shown in FIG. 4B can include an outer layer420. The outer layer 420 can be formed from, for example, variouspolymers such as formed thermoplastic. In some implementations, theouter layer 420 can be constructed from an ethylene acid copolymer. Insome examples, a copolymer having a low water vapor transmission ratecan be chosen. For example, the outer layer 420 can be constructed froman ionomer resin of ethylene acid copolymer such as DuPont™ Surlyn® asdescribed above. Such a resin can be processed in conventional blownfilm, cast film, sheet extrusion and coextrusion equipment designed toprocess polyethylene and ethylene copolymer type resins. The ionomerresin can be configured to have a relatively low water vaportransmission rate (e.g., approximately 0.8 g/100 in²/day). For example,a material with a low permeability such as an ionomer resin can providean advantage of a longer shelf-life of the conductive gel deploymentdevice relative to conventional configurations as the rate ofevaporation of the conductive gel through the ionomer resin is low.Thus, the conductive gel inside the conductive gel reservoirs (e.g.,conductive gel reservoirs 404) can maintain its original viscosity whenstored in the conductive gel reservoirs for an extended period of time(e.g., for a period of two or more years).

In some examples, the outer layer 420 can be manufactured from theionomer resin using a vacuum forming machine. A vacuum forming processcan be used to form a sheet of the ionomer resin into the outer layer420. An appropriately sized sheet of the ionomer resin can be placedinto the vacuum forming machine along with a mold or plate including anegative of the features to be formed on the outer layer 420. The sheetof the ionomer resin can be appropriately heated, stretched against themold, and pressed against the mold by a vacuum pressure. After thepressure is released, the sheet of ionomer resin has been molded intothe outer layer 420. Based upon the resulting desired characteristics ofthe outer layer 420, the physical properties of the ionomer resin sheetcan be chosen or adjusted accordingly. For example, the thickness of theionomer resin sheet can be selected based upon the desired flexibilityof the finished outer layer 420 as well as the pressures that will beexerted on the outer layer 420. In some examples, the thickness of theionomer resin sheet can be between 0.0095-0.0120 inches thick. Incertain implementations, the thickness of the ionomer resin sheet can be0.011 inches thick. Additional characteristics such as resin density andother related properties can also be determined based upon resultingdesired characteristics of the finished outer layer 420.

The outer layer 420 can include multiple gel reservoir top portions 422.The gel reservoir top portions 422 can be formed to provide an airpocket as well as a surface against which a pressurized fluid can exerta pressure when applied to a conductive gel reservoir 404. Similarly,the outer layer 420 can include a pressure source top portion 424. Thepressure source top portion 424 can be arranged to define a cavity forinsertion and containment of, for example, pressure source 406.

The multilayer assembly as shown in FIG. 4B can also include a diaphragmlayer 430. Like the outer layer 420, the diaphragm layer 430 can beformed from, for example, an ionomer resin. As before, a vacuum formingprocess can be used to form a sheet of the ionomer resin into thediaphragm layer 430. An appropriately sized sheet of the ionomer resincan be placed into the vacuum forming machine along with a mold or plateincluding a negative of the features to be formed on the diaphragm layer430. The sheet of the ionomer resin can be appropriately heated,stretched against the mold, and pressed against the mold by a vacuumpressure. After the pressure is released, the sheet of ionomer resin hasbeen molded into the diaphragm layer 430. Based upon the resultingdesired characteristics of the diaphragm layer 430, the physicalproperties of the ionomer resin sheet can be chosen or adjustedaccordingly. For example, the thickness of the ionomer resin sheet canbe selected based upon the desired flexibility of the finished diaphragmlayer 430. In some examples, the thickness of the ionomer resin sheetcan be between 0.0095-0.0120 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.011 inches thick.Additional characteristics such as resin density and other relatedproperties can also be determined based upon resulting desiredcharacteristics of the finished diaphragm layer 430.

The diaphragm layer 430 can also include multiple gel reservoir innerportions 432. The gel reservoir inner portions 432 can be formed suchthat, upon layering of the outer layer 420 and the diaphragm layer 430,a small air gap is defined between each gel reservoir top portion 422and a corresponding gel reservoir inner portion 432. As such, the gelreservoir inner portions 432 can be sized slightly smaller than the gelreservoir top portions 422. This size difference allows the smaller gelreservoir inner portions 432 to nest within the gel reservoir topportions 422 and define the air gap there-between. With such anarrangement of components, upon application of an exerted pressure froma pressurized fluid, pressure within the air gap can increase until anadhesive seal ruptures. When the adhesive seal ruptures, the exertedpressure can deform the gel reservoir inner portion 432, thereby causingflow of the conductive gel contained within that conductive gelreservoir 404.

The multilayer assembly as shown in FIG. 4B can further include alidding layer 440. The lidding layer 440 is configured to adhere to thediaphragm layer 430 to provide a sealing surface for holding theconductive gel within gel reservoir inner portions 432 of the diaphragmlayer 430. The lidding layer 440 can be formed from, for example, apolyester film that includes a heat sealable adhesive layer. In someexamples, Scotchpak™ MA250M Medical Adhesion Film can be used for theconstruction of the lidding layer 440. Similar to the ionomer resinsheet as described above, the thickness of the polyester film can beselected based upon the desired flexibility of the finished liddinglayer 440. In some examples, the thickness of the ionomer resin sheetcan be between 0.00230-0.00260 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.00245 inches thick.Additionally, like the ionomer resin as described above, a polyesterfilm with a low permeability and water vapor transmission rate can beselected. Additional characteristics such as adhesive density and otherrelated properties can also be determined based upon resulting desiredcharacteristics of the finished lidding layer 440.

As described above, the lidding layer 440 can be configured to act asbarrier layer preventing unwanted release of the conductive gel from theconductive gel reservoirs 404. As such, the adhesive seals 410 can beplaced between the diaphragm layer 430 and the lidding layer 440.Similarly, the lidding layer 440 includes exit ports 412 (as shown inFIG. 4A) positioned adjacent to (or, if a ring-shaped adhesive seal isused, in the center of) the adhesive seals 410.

When manufactured, the outer layer 420, the diaphragm layer 430 and thelidding layer 440 can be combined into a multilayer gel deploymentdevice 401. As noted above, the gel deployment device 401 can beconfigured to deploy an amount of conductive gel prior to applicationof, for example, a therapeutic shock.

As noted above, a therapy electrode 400 can also include an electricallyconductive layer 450. The electrically conductive layer 450 can beformed from a conductive material such as metal foil or another thin,pliable conductive material. For example, the electrically conductivelayer 450 can be constructed from rolled stainless steel. In someexamples, the thickness of the electrically conductive layer 450 can bebetween 0.00295-0.00305 inches thick. In certain implementations, thethickness of the electrically conductive layer 450 can be 0.003 inchesthick.

The electrically conductive layer 450 can be configured to be positionedsubstantially proximate to the patient's skin and to direct atherapeutic shock towards the patient's skin. Depending upon the design,the electrically conductive layer 450 can also be integrated directlyinto the garment, e.g., garment 110 as described above. In certainimplementations, the electrically conductive layer 450 is positioned andconfigured to work in concert with the gel deployment device 401. Thisprovides for a replaceable gel deployment device 401 that can bereplaced without replacing the electrically conductive layer 450 aswell.

Additionally, the electrically conductive layer 450 can include a seriesof apertures 452. The apertures 452 can be arranged in a similargeometry as the placement of the adhesive seals 410 and the exit ports412 (as shown, for example, in FIG. 4A). Such an arrangement ofcomponents provides for conductive gel flow through the exit ports 412and then through the apertures 452 in the electrically conductive layer450 and onto a patient's skin.

As noted above, each of the lidding layer 440 and the electricallyconductive layer 450 includes one or more exit ports in the liddinglayer 440 (e.g., exit ports 412 as shown in FIG. 4A) and apertures 452in the electrically conductive layer 450 positioned such that the exitports 412 and apertures 452 are aligned with the open center portion ofgel reservoir cluster 403. Depending upon the manufacturing process, theexit ports 412 and apertures 452 can be formed in the lidding layer 440and the electrically conductive layer 450 prior to or during assembly ofthe multilayer device illustrated in FIG. 4B. For example, the opencenter portion of the gel reservoir clusters 403 can be used to align apiercing device configured to pierce the multilayered device to producethe exit ports 412 and the apertures 452. However, if such a process isused, for example, to stamp out the exit ports 412 and the apertures 452after assembly of the multilayered assembly, a sealant or adhesive plug(not shown in FIG. 4B) can be applied to the outer layer 420 to preventunwanted fluid flow upon release of the conductive gel.

In an example manufacturing process, each layer as shown in FIG. 4B canconfigured to be adhered to its adjacent layers via an adhesion process.For example, each of the outer layer 420 and the diaphragm layer 430 canbe bonded together directly. Heat and pressure can be applied to each ofthe outer layer 420 and the diaphragm layer 430 to, e.g., chemicallybond the two layers together. As noted above, the lidding layer 440 canbe manufactured from a polyester film that includes a heat-activatedadhesive. In such an arrangement of components, the diaphragm layer 430(or the combined top layer 420 and diaphragm layer 430) can bepositioned on top of the lidding layer 440 such that the lidding layer440 acts to seal the conductive gel in the gel reservoir inner portions432 of the diaphragm layer 430. Heat can be applied to the stackedstructure, thereby forming the multilayer gel deployment device asdescribed above. Additionally, an amount of heat-activated adhesive (oranother similar adhesive) can be applied between the lidding layer 440and the electrically conductive layer 450. The electrically conductivelayer 450 can then be adhered to the lidding layer 440 (and,subsequently, the multilayered gel deployment device), thereby resultingin a complete therapy electrode 400.

In certain implementations, the therapy electrode 400 can be configuredto include one or more ventilation holes (e.g., similar to ventilationholes 226, 234 and 242 as shown in FIG. 2C) or one or more openings(e.g., similar to opening 254 shown in FIG. 2C) in the electricallyconductive layer 450 to increase edge length. FIGS. 4A and 4B areprovided by way of example only and can be altered to include additionalfeatures such as the ventilation holes and openings in the electricallyconductive layer as described above.

In operation, the therapy electrode 400 as describe above can beconfigured to provide a therapeutic shock to a patient currentexperiencing, for example, a cardiac arrhythmia. Prior to delivering theshock, the conductive gel deployment device 401 associated with thetherapy electrode 400 can be configured to deploy the conductive gelonto the patient's skin. Initially, the pressure source 406 can betriggered to produce an increased fluid pressure in the fluid channel408. The increased fluid pressure can cause internal pressure within theair gaps between each gel reservoir top portion 422 and itscorresponding gel reservoir inner portion 432 to increase. As theinternal pressure within the conductive gel reservoirs 404 increases, adistributed pressure can be applied about the perimeter of each of theadhesive seals 410 for each of the reservoir clusters 403. After thedistributed pressure reaches a high enough level (e.g., 8-22 psi), eachindividual adhesive seal 410 can begin to rupture, causing the releaseof the conductive gel from each of the conductive gel reservoirs 404.Pressure within each of the conductive gel reservoirs 404 can causedeformation of the gel reservoir inner portion 432, which results in theconductive gel being pushed out of the conductive gel reservoirs 404.The conductive gel can flow through the exit ports 412 for eachreservoir cluster 403 and can be distributed on the electricallyconductive surface 450 and the patient's skin. After gel deployment, theelectrically conductive surface 450 can direct the therapeutic shockthrough the conductive gel, which conducts the therapeutic shock to thepatient's skin.

As described above in the description of FIGS. 2A-2C, and 4A and 4B, aconductive gel reservoir (or a cluster of conductive gel reservoirs) canbe arranged such that it surrounds a single adhesive seal. With such anarrangement of components, a pressure exerted on the adhesive seal issubstantially equally distributed about the perimeter of the adhesiveseal. However, additional conductive gel reservoir designs can be usedthat also improve distribution of an exerted pressure as compared toconventional designs. For example, as shown in FIG. 5, a conductive gelreservoir 500 can have a U or horseshoe shape such that the conductivegel reservoir 500 partially surrounds its adjacent adhesive seal 502.For example, the conductive gel reservoir 500 can be configured tosurround approximately 180°-345° of the adhesive seal 502. In certainimplementations, the conductive gel reservoir 500 can be configured tosurround approximately 315° of adhesive seal 502. However, when apressure is exerted on the conductive gel reservoir 500, the conductivegel reservoir exerts a similar pressure about the perimeter of theadhesive seal 502. As indicated by the various arrows shown in FIG. 5,the exerted pressure can be applied to the adhesive seal 502 at multiplepoints about the perimeter of the adhesive seal 502.

The configuration as shown in FIG. 5 can offer an advantage over aconfiguration involving an adhesive seal configured to rupture frompressure being applied at only a single point. For instance, multiplepoints of applied pressure to the adhesive seal 502 can improve alikelihood that the adhesive seal 502 will be subjected to pressures ator about the predetermined pressure level configured to rupture theadhesive seal 502, thereby increasing the likelihood that each of themultiple points of the adhesive seal 502 will rupture, providing morearea for the conductive gel to flow out of the conductive gel reservoir500.

It should be noted that the size and shape of conductive gel reservoir500 as shown in FIG. 5 is by way of example, and various other sizes andshapes can be included. For example, the conductive gel reservoir 500can have a semi-circular shape configured to surround about 180° of theperimeter of the adhesive seal 502. In certain implementations, theconductive gel reservoir 500 can have a C-shape configured to surroundabout 210°-270° of the perimeter of the adhesive seal 502.

In some implementations, a gel deployment device can include fluidconduits fluidly connected to one or more conductive gel reservoirs. Insuch an implementation, when a pressurized fluid is applied to theconductive gel reservoir, the pressure exerted by the pressurized fluidis distributed about a perimeter of an adhesive seal positioned betweenthe conductive gel reservoir and a fluid conduit. Once the pressurereaches a predetermined pressure level configured to rupture theadhesive seal (e.g., in the range of 8-22 psi), the adhesive sealruptures, thereby resulting in release of the conductive gel stored inthe conductive gel reservoir. After release, the conductive gel can flowthrough the fluid conduits to multiple exit ports along the path of thefluid conduit. With such an arrangement of components, multiple exitports can be in fluid connection with a single adhesive seal, therebyreducing the number of adhesive seals used in the gel deployment device.Additionally, such an arrangement of components has the advantage ofreducing or eliminating leaking due to improperly ruptured adhesiveseals. In certain embodiments, if an adhesive seal were to prematurelyrupture, the released conductive gel would can flow into the fluidconduits and remain there until an applied pressure pushes theconductive gel through the fluid conduits to the exit ports.

FIGS. 6A and 6B illustrates a therapy electrode 600 including aconductive gel deployment device 601 that uses conductive gel reservoirshaving gel conduits for directing conductive gel flow. Thisconfiguration can include, for example, redundant adhesive seals foreach conductive gel reservoir (e.g., two or more adhesive seals for eachgel conduit). Upon application of pressure to the conductive gelreservoirs (e.g., from a pressure source as described in further detailbelow), the conductive gel in turn exerts a pressure on the adhesiveseals until one or more of the adhesive seals rupture. The pressure thenaids in the flow of the conductive gel through one or more conductivegel conduits to one or a series of distributed exit ports. For example,the exit ports can be spaced apart on the substrate to allow for evendistribution of the conductive gel on a conductive surface in proximityto the patient's skin.

FIG. 6A illustrates a therapy electrode 600 that includes a conductivegel deployment device 5601 using, for example in this configuration,multiple gel conduits 614 for distribution of conductive gel. Liketherapy electrode 200, the therapy electrode 600 can be a multiple layerlaminated structure that includes an electrically conductive layer 650(shown in FIG. 6B and explained in greater detail below). In use, theelectrically conductive layer 650 can be disposed substantiallyproximate to the patient's skin, although the conductive layer need notmake direct contact with the patient (e.g., in implementations whereconductive portions of the garment 110 act as an interface between theconductive layer 650 and the patient's skin, and/or implementationswhere portions of the patient's clothing may be present between theelectrically conductive layer 650 and the patient's skin). In someimplementations, the garment 110 can include a pocket or other similarstructure including a metallic mesh that can be configured to act as aninterface between the electrically conductive layer 650 and thepatient's skin. Upon deployment of the conductive gel, an electricalpathway can be defined between the electrically conductive layer 650 andthe patient's skin.

As shown in FIG. 6A, the therapy electrode 600 can include a substrate602 about which various components of the gel deployment device 601 canbe arranged. The substrate 602 can include a plurality of conductive gelreservoirs 604 distributed about the surface of the substrate 602. Incertain implementations, the conductive gel reservoirs 604 can bedisposed about a first side of the substrate 602 (e.g., a top portion ofthe substrate 602 as depicted in the plan view of FIG. 6A and positionedopposite a bottom portion or side of the therapy electrode 600 thatincludes, for example, the conductive layer 650). Each of the conductivegel reservoirs 604 can be configured to hold a volume of conductive gel.Depending upon the total number of conductive gel reservoirs 604 used,the amount of conductive gel contained within each conductive gelreservoir 604 can be adjusted accordingly. For example, the geldeployment device 601 can include approximately 3-20 ml of conductivegel. In other examples, the gel deployment device 601 can be configuredto hold between 5-15 ml of conductive gel. The conductive gel can bedistributed amongst each of the conductive gel reservoirs 604. Forexample, each conductive gel reservoir 604 can be configured to holdapproximately 0.5-5.0 ml of conductive gel. In other examples, eachconductive gel reservoir 604 can be configured to hold between 1.0 and4.0 ml of conductive gel. In come implementations, depending upon thenumber and shape of the conductive gel reservoirs 604, additionalquantities of conductive gel can be included in each conductive gelreservoir 604. For example, each conductive gel reservoir 604 can beconfigured to hold 6 ml of conductive gel, 7 ml of conductive gel, 8 mlof conductive gel, 9 ml of conductive gel, or 10 ml of conductive gel.As such, by varying the amount of total conductive gel held within eachconductive gel reservoir 604, the total amount of gel contained withingel deployment device 601 can be adjusted.

In certain embodiments, the amount of conductive gel in each of theconductive gel reservoirs 604 can be equal or substantially equal suchthat the total amount of conductive gel is distributed among each of theconductive gel reservoirs 604. In other examples, the amount ofconductive gel in each of the conductive gel reservoirs 604 can vary.

As shown in the example gel deployment device 601 illustrated in FIG.6A, with three conductive gel reservoirs 604, each conductive gelreservoir 604 can hold approximately 3.34 ml of conductive gel. As notedabove, in other examples, a gel deployment device can be configured tohold between approximately 3 ml and 20 ml of conductive gel. The amountof conductive gel can be determined based upon the number of reservoirsbeing used as well as the size of the electrically conductive layer theconductive gel is configured to be deployed on.

Additionally, the therapy electrode 600 can also include a set ofconductive gel reservoir protective caps like protective caps 205 and405 as described above. The protective caps can be configured to coverthe conductive gel reservoirs 604 to provide protection. In certainimplementations, the protective caps can be made from a hard plasticsuch as polystyrene or polycarbonate. The protective caps can be sized(e.g., have a preconfigured thickness) such that the protective capsprovide a rigid outer structure for absorbing any accidental force orpressure exerted on the outside of the conductive gel reservoirs 604prior to release of the conductive gel contained therein. In certainconfigurations, each of the conductive gel reservoirs 604 can have asingle protective cap. In other implementations, the protective caps canbe sized to protect multiple conductive gel reservoirs 604.

Each of the conductive gel reservoirs 604 can also include one or moreadjacent adhesive seals 610, such as ring-shaped adhesive seals. Asshown in FIG. 6A, each conductive gel reservoir can include two adhesiveseals 610, thereby providing for a redundant release mechanism for theconductive gel contained within each conductive gel reservoir 604. Theadhesive seals 610 are positioned such that they can prevent release ofthe conductive gel to the exit ports 612 (via the gel conduits 614).

The therapy electrode 600 can further include a pressure source 606connected to a fluid channel 608. The pressure source 606, whenactivated by an activation signal, can release a fluid, such ascompressed gas, into the fluid channel 608. The hydraulic pressure ofthe fluid from the activated fluid pressure source 606 in the fluidchannel 608 facilitates release of the adhesive seals 610 at or aboutsubstantially at a predetermined pressure level configured to rupturethe adhesive seal 610. In an example, as a result of the position of theadhesive seals 610 relative to their adjacent conductive gel reservoir604, the pressure exerted by the pressure source 606 can cause theconductive gel to, in turn, exert a pressure against the adhesive seals610. Thus, the adhesive seals 610 can be configured to rupture at one ormore points where the conductive gel exerts the pressure on the adhesiveseal 610 (or in a continuous portion of the adhesive seal 610 in contactwith the conductive gel), at or about substantially at the predeterminedpressure level configured to rupture the adhesive seal 610, therebyresulting in release of the conductive gel from each conductive gelreservoir 604.

As shown in FIG. 6A, adhesive seals 610 can be ring-shaped adhesiveseals. In such an arrangement, the adhesive seal 610 can includemultiple barriers to prevent conductive gel flow. For example, as shownin FIG. 6A, the portion of the adhesive seal 610 that is positionedsubstantially proximate to the conductive gel reservoir 604 (i.e., thetop portion of the seal 610 as shown in FIG. 6A) can provide a firstbarrier configured to prevent release of the conductive gel from theconductive gel reservoir 604. Similarly, the portion of the adhesiveseal 610 that is positioned substantially proximate to the gel conduit614 (i.e., the bottom portion of the ring-shaped adhesive seal 610 asshown in FIG. 6A) can provide a second barrier. In the event of apremature failure of the top portion of the adhesive seal 610, thebottom portion of the adhesive seal 610 can provide a redundant seal,thereby lowering the chances of a leaking conductive gel reservoir ascompared to designs with a single adhesive seal barrier. Thus, in suchan example, once the pressure exerted by the conductive gel has rupturedthe top portion of the adhesive seal 610, the conductive gel can flowthrough the adhesive seal 610 until the conductive gel contacts thebottom portion of the adhesive seal 610. As before, the conductive gelcan apply a pressure to the bottom portion of the adhesive seal 610,thereby causing the bottom portion to rupture. The conductive can thenflow into one of the gel conduits 614.

It should be noted that ring-shaped adhesive seals are shown in FIG. 6Aand described above by way of example only. In certain implementations,the adhesive seal can be shaped as a straight or curved line that isconfigured to define a single barrier to prevent conductive gel flow.Such an implementation can be advantageous when the design includes afluid pressure source configured to release a pressurized fluid having alower pressure, e.g., 4-15 psi. In such an example, as a result of thelower pressure of the pressurized fluid, it can be advantageous to havea single barrier that is configured to be ruptured prior to conductivegel release.

Upon release of the adhesive seals 610, the conductive gel stored ineach of the plurality of conductive gel reservoirs 604 can flow into oneof the gel conduits 614. The released conductive gel can continue toflow through the gel conduits 614 to the plurality of exit ports 612.The conductive gel can then flow through apertures formed in theelectrically conductive layer 650 and onto the exposed surface of theelectrically conductive layer 650 proximate to the patient's skin. Theapertures in the electrically conductive layer 650 are substantiallyaligned with the plurality of exit ports 612 so that, when released, theelectrically conductive gel is dispensed onto the exposed surface of theelectrode portion that is disposed substantially proximate to thepatient's body.

It should be noted that the arrangement and position of both the gelconduits 614 and the exit ports 612 as shown in FIG. 6A is by way ofexample only. For example, the path of conductive gel flow as defined bythe gel conduits 614 can include a curved or other non-linear shape inaddition to the linear shape shown in FIG. 6A. Similarly, more or lessthan the three exit ports 612 per gel conduit 614 as shown in FIG. 6Acan be included. Thus, by altering the shape of the gel conduits 614 andthe number of exit ports 612, the conductive gel can be more evenlydistributed about the therapy electrode 600 without increasing thenumber of conductive gel reservoirs 604 and adhesive seals 610.

FIG. 6B illustrates an exploded view of the therapy electrode 600,showing the multiple layers included in the manufacturing process of thetherapy electrode 600. In certain implementations, a set of layers asshown in FIG. 6B (e.g., layer 620, 630 and 640 as described in greaterdetail below) can be assembled to manufacture the gel deployment device601. It should be noted that the details provided in FIG. 6B andexplained herein, as well as the overall process discussed below, isprovided by way of example only. For example, changes to the techniquesand configurations described herein can be implemented withoutsubstantially deviating from the scope of the disclosure.

The multilayer assembly as shown in FIG. 6B can include an outer layer620. The outer layer 620 can be formed from, for example, variouspolymers such as formed thermoplastic. In some implementations, theouter layer 620 can be constructed from an ethylene acid copolymer. Insome examples, a copolymer having a low water vapor transmission ratecan be chosen. For example, the outer layer 620 can be constructed froman ionomer resin of ethylene acid copolymer such as DuPont™ Surlyn® asdescribed above. Such a resin can be processed in conventional blownfilm, cast film, sheet extrusion and coextrusion equipment designed toprocess polyethylene and ethylene copolymer type resins. The ionomerresin can be configured to have a relatively low water vaportransmission rate (e.g., 0.8 g/100 in²/day). For example, a materialwith a low permeability such as an ionomer resin can provide anadvantage of a longer shelf-life of the conductive gel deployment devicerelative to conventional configurations as the rate of evaporation ofthe conductive gel through the ionomer resin is low. Thus, theconductive gel inside the conductive gel reservoirs (e.g., conductivegel reservoirs 604) can maintain its original viscosity when stored inthe conductive gel reservoirs for an extended period of time (e.g., fora period of two or more years).

In some examples, the outer layer 620 can be manufactured from theionomer resin using a vacuum forming machine. A vacuum forming processcan be used to form a sheet of the ionomer resin into the outer layer620. An appropriately sized sheet of the ionomer resin can be placedinto the vacuum forming machine along with a mold or plate including anegative of the features to be formed on the outer layer 620. The sheetof the ionomer resin can be appropriately heated, stretched against themold, and pressed against the mold by a vacuum pressure. After thepressure is released, the sheet of ionomer resin has been molded intothe outer layer 620. Based upon the resulting desired characteristics ofthe outer layer 620, the physical properties of the ionomer resin sheetcan be chosen or adjusted accordingly. For example, the thickness of theionomer resin sheet can be selected based upon the desired flexibilityof the finished outer layer 620 as well as the pressures that will beexerted on the outer layer 620. In some examples, the thickness of theionomer resin sheet can be between 0.0095-0.0120 inches thick. Incertain implementations, the thickness of the ionomer resin sheet can be0.011 inches thick. Additional characteristics such as resin density andother related properties can also be determined based upon resultingdesired characteristics of the finished outer layer 620.

The outer layer 620 can include multiple gel reservoir top portions 622.The gel reservoir top portions 622 can be formed to provide an airpocket as well as a surface against which a pressurized fluid can exerta pressure when applied to a conductive gel reservoir 604. Similarly,the outer layer 620 can include a pressure source top portion 624. Thepressure source top portion 624 can be arranged to define a cavity forinsertion and containment of, for example, pressure source 606.

The multilayer assembly as shown in FIG. 6B can also include a diaphragmlayer 630. Like the outer layer 620, the diaphragm layer 630 can beformed from, for example, an ionomer resin. As before, a vacuum formingprocess can be used to form a sheet of the ionomer resin into thediaphragm layer 630. An appropriately sized sheet of the ionomer resincan be placed into the vacuum forming machine along with a mold or plateincluding a negative of the features to be formed on the diaphragm layer630. The sheet of the ionomer resin can be appropriately heated,stretched against the mold, and pressed against the mold by a vacuumpressure. After the pressure is released, the sheet of ionomer resin hasbeen molded into the diaphragm layer 630. Based upon the resultingdesired characteristics of the diaphragm layer 630, the physicalproperties of the ionomer resin sheet can be chosen or adjustedaccordingly. For example, the thickness of the ionomer resin sheet canbe selected based upon the desired flexibility of the finished diaphragmlayer 630. In some examples, the thickness of the ionomer resin sheetcan be between 0.0095-0.0120 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.011 inches thick.Additional characteristics such as resin density and other relatedproperties can also be determined based upon resulting desiredcharacteristics of the finished diaphragm layer 630.

The diaphragm layer 630 can also include multiple gel reservoir innerportions 632. The gel reservoir inner portions 632 can be formed suchthat, upon layering of the outer layer 620 and the diaphragm layer 630,a small air gap is defined between each gel reservoir top portion 622and a corresponding gel reservoir inner portion 632. As such, the gelreservoir inner portions 632 can be sized slightly smaller than the gelreservoir top portions 622. This size difference allows the smaller gelreservoir inner portions 632 to nest within the gel reservoir topportions 622 and define the air gap there-between. With such anarrangement of components, upon application of an exerted pressure froma pressurized fluid, pressure within the air gap can increase until anadjacent adhesive seal ruptures. When the adhesive seal ruptures, theexerted pressure can deform the gel reservoir inner portion 632, therebycausing flow of the conductive gel contained within that conductive gelreservoir 604.

The multilayer assembly as shown in FIG. 6B can further include alidding layer 640. The lidding layer 640 is configured to adhere to thediaphragm layer 630 to provide a sealing surface for holding theconductive gel within gel reservoir inner portions 632 of the diaphragmlayer 630. The lidding layer 640 can be formed from, for example, apolyester film that includes a heat sealable adhesive layer. In someexamples, Scotchpak™ MA250M Medical Adhesion Film can be used for theconstruction of the lidding layer 640. Similar to the ionomer resinsheet as described above, the thickness of the polyester film can beselected based upon the desired flexibility of the finished liddinglayer 640. In some examples, the thickness of the ionomer resin sheetcan be between 0.00230-0.00260 inches thick. In certain implementations,the thickness of the ionomer resin sheet can be 0.00245 inches thick.Additionally, like the ionomer resin as described above, a polyesterfilm with a low permeability and water vapor transmission rate can beselected. Additional characteristics such as adhesive density and otherrelated properties can also be determined based upon resulting desiredcharacteristics of the finished lidding layer 640.

As described above, the lidding layer 640 can be configured to act asbarrier layer preventing unwanted release of the conductive gel from theconductive gel reservoirs 604. As such, the adhesive seals 610 can beplaced between the diaphragm layer 630 and the lidding layer 640.Similarly, the lidding layer 640 includes exit ports 612 positionedadjacent to the adhesive seals 610. Additionally, the lidding layer 640can include one or more pathway features used to define the fluidconduits 614. For example, one or more pieces of porous material such asfoam can be positioned appropriately on the lidding layer 640 such that,when placed against the diaphragm layer 630, the foam pieces act todefine the fluid conduits 614.

When manufactured, the outer layer 620, the diaphragm layer 630 and thelidding layer 640 can be combined into the multilayer gel deploymentdevice 601. As noted above, the gel deployment device 601 can beconfigured to deploy an amount of conductive gel prior to applicationof, for example, a therapeutic shock.

As noted above, a therapy electrode 600 can also include an electricallyconductive layer 650. The electrically conductive layer 650 can beformed from a conductive material such as metal foil or another thin,pliable conductive material. For example, the electrically conductivelayer 650 can be constructed from rolled stainless steel. In someexamples, the thickness of the electrically conductive layer 650 can bebetween 0.00295-0.00305 inches thick. In certain implementations, thethickness of the electrically conductive layer 650 can be 0.003 inchesthick.

The electrically conductive layer 650 can be configured to be positionedsubstantially proximate to the patient's skin and to direct atherapeutic shock towards the patient's skin. Depending upon the design,the electrically conductive layer 650 can also be integrated directlyinto the garment, e.g., garment 110 as described above. In certainimplementations, the electrically conductive layer 650 is positioned andconfigured to work in concert with the gel deployment device 601. Thisprovides for a replaceable gel deployment device 601 that can bereplaced without replacing the electrically conductive layer 650 aswell.

Additionally, the electrically conductive layer 650 can include a seriesof apertures 652. The apertures 652 can be arranged in a similargeometry as the placement of the adhesive seals 610 and the exit ports612. Such an arrangement of components provides for conductive gel flowthrough the exit ports 612 and then through the apertures 652 in theelectrically conductive layer 650 and onto a patient's skin.

In an example manufacturing process, each layer as shown in FIG. 6B canbe configured to be adhered to its adjacent layers via an adhesionprocess. For example, each of the outer layer 620 and the diaphragmlayer 630 can be bonded together directly. Heat and pressure can beapplied to each of the outer layer 620 and the diaphragm layer 630 to,e.g., chemically bond the two layers together. As noted above, thelidding layer 640 can be manufactured from a polyester film thatincludes a heat-activated adhesive. In certain implementations, thediaphragm layer 630 (or the combined top layer 620 and diaphragm layer630) can be positioned on top of the lidding layer 640 such that thelidding layer 640 acts to seal the conductive gel in the gel reservoirinner portions 632 of the diaphragm layer 630. Heat can be applied tothe stacked structure, thereby forming the multilayer gel deploymentdevice as described above. Additionally, an amount of heat-activatedadhesive (or another similar adhesive) can be applied between thelidding layer 640 and the electrically conductive layer 650. Theelectrically conductive layer 650 can then be adhered to the liddinglayer 640 (and, subsequently, the multilayered gel deployment device),thereby resulting in a complete therapy electrode 600.

In certain implementations, the therapy electrode 600 can be configuredto include one or more ventilation holes (e.g., similar to ventilationholes 226, 234 and 242 as shown in FIG. 2C) or more or more openings(e.g., similar to opening 254 as shown in FIG. 2C) in the electricallyconductive layer to increase edge length. FIGS. 6A and 6B are providedby way of example only to and can be altered to include additionalfeatures such as the ventilation holes and openings in the electricallyconductive layer as described above.

In operation, the therapy electrode 600 as describe above can beconfigured to provide a therapeutic shock to a patient currentexperiencing, for example, a cardiac arrhythmia. Prior to delivering theshock, the conductive gel deployment device 601 associated with thetherapy electrode 5600 can be configured to deploy the conductive gelonto the patient's skin. Initially, the pressure source 606 can betriggered to produce an increased fluid pressure in the fluid channel608. The increased fluid pressure can cause internal pressure within theair gaps between each gel reservoir top portion 622 and itscorresponding gel reservoir inner portion 632 to increase. As theinternal pressure within the conductive gel reservoirs 604 increases, adistributed pressure can be applied to each of the adhesive seals 610.After the distributed pressure reaches a high enough level (e.g., 8-22psi), each individual adhesive seal 610 can begin to rupture, causingthe release of the conductive gel from each of the conductive gelreservoirs 604. Pressure within each of the conductive gel reservoirs604 can cause deformation of the gel reservoir inner portion 632, whichresults in the conductive gel being pushed out of the conductive gelreservoirs 604. The distributed pressure can facilitate gel flow intothe gel conduits 614 and through each of the exit ports 612. Theconductive gel can flow through the exit ports 612 and can bedistributed on the electrically conductive surface 650 and the patient'sskin. After conductive gel deployment, the electrically conductivesurface 650 can direct the therapeutic shock through the conductive gel,which conducts the therapeutic shock to the patient's skin.

Use of a Gel Deployment Device with an Ambulatory Medical Device

FIG. 7 depicts an example of conductive gel entering the area between atherapy electrode and the patient's skin after being released by, forexample, one of the gel deployment devices as described above (e.g., geldeployment devices 201, 401 and 601 as shown in FIGS. 2C, 4B and 6B). Inone implementation, the conductive gel can enter the area between aconductive surface 705 of therapy electrode 700 and the patient's skin,and can form a conduction path 710 from the therapy electrode 700 to thepatient's skin. The conductive gel can cover conductive thread or meshfabric 715 that is part of a garment (e.g., garment 110), portions ofwhich can be disposed between the patient's skin and the therapyelectrode 700. For example, the gel deployment device can be configuredin a form of a removable receptacle. As such, after the gel is deployed,the gel deployment device can be removed and replaced.

FIG. 8 illustrates components of external medical device 800 accordingto certain implementations, with sensing electrodes 850 including atleast one EKG (or ECG) electrocardiogram sensor, conductive thread 805woven into belt 810 of garment 110, and gel deployment device 845disposed proximate to a first therapy electrode 835 in garment 810.

In one implementation, a control unit 850 can instruct the geldeployment device 845 to release the conductive gel included inconductive gel reservoir 855. The released conductive gel can reduceimpedance between the patient's skin and first therapy electrode 835.Therapy controller 815 can apply treatment (e.g., a shock) to thepatient via first therapy electrode 835 and second therapy electrode 840(that can include another gel deployment device 845 for deployment ofconductive gel between second therapy electrode 840 and the patient'sskin). During treatment, current can follow a path between the patient'sskin and first therapy electrode 835 and second therapy electrode 840via the conductive gel.

Although the subject matter contained herein has been described indetail for the purpose of illustration, it is to be understood that suchdetail is solely for that purpose and that the present disclosure is notlimited to the disclosed embodiments, but, on the contrary, is intendedto cover modifications and equivalent arrangements that are within thespirit and scope of the appended claims. For example, it is to beunderstood that the present disclosure contemplates that, to the extentpossible, one or more features of any embodiment can be combined withone or more features of any other embodiment.

Other examples are within the scope and spirit of the description andclaims. Additionally, certain functions described above can beimplemented using software, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions can alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

What is claimed is:
 1. A gel deployment device for use with anelectrotherapy system, the device comprising: a substrate; a pluralityof gel reservoirs disposed on the substrate, each of the plurality ofgel reservoirs comprising a volume of a conductive gel and positionedsubstantially adjacent to a seal; wherein the seal is configured torelease the conductive gel from at least one of the plurality of gelreservoirs in response to pressure being applied about a perimeter ofthe seal; and at least one conductive surface configured to come intocontact with the released conductive gel and to deliver a therapeuticcurrent to a body of a patient.
 2. The device of claim 1, wherein theconductive gel is capable of conducting the therapeutic current from theat least one conductive surface to the patient's skin.
 3. The device ofclaim 1, wherein the at least one conductive surface comprises at leastone opening configured to define an inner edge within the at least oneconductive surface.
 4. The device of claim 1, wherein the substratecomprises one or more ventilation holes configured to facilitate airflow through the gel deployment device.
 5. The device of claim 1,wherein at least one of the plurality of gel reservoirs is oriented onthe substrate such that the at least one of the plurality of gelreservoirs surrounds the seal.
 6. The device of claim 5, wherein the atleast one of the plurality of gel reservoirs is configured to exert anapplied pressure at multiple points about the perimeter of thesurrounded seal.
 7. The device of claim 5, wherein the at least one ofthe plurality of gel reservoirs is configured to exert an appliedpressure substantially equally about the perimeter of the surroundedseal.
 8. The device of claim 5, wherein each of the plurality of gelreservoirs comprises a donut shape defining an open center portion,wherein the seal is positioned within the open center portion of each ofthe donut shaped gel reservoirs.
 9. The device of claim 5, wherein eachof the plurality of gel reservoirs comprises a polygon shape defining anopen center portion, wherein the seal is positioned within the opencenter portion of each of the polygon shaped gel reservoirs.
 10. Thedevice of claim 1, wherein at least one of the plurality of gelreservoirs is shaped such that it partially surrounds the seal.
 11. Thedevice of claim 1, further comprising at least one reservoir clustercomprising two or more gel reservoirs.
 12. The device of claim 11,wherein the at least one reservoir cluster is configured such that thetwo or more gel reservoirs are positioned about a center point, therebydefining an open center portion, wherein the seal is positioned withinthe open center portion of the at least one reservoir cluster.
 13. Thedevice of claim 12, wherein, upon application of the distributedpressure, the seal positioned within the open center portion of the atleast one reservoir cluster is configured to release the conductive gelfrom each of the two or more of the plurality of gel reservoirs in theat least one reservoir cluster substantially simultaneously.
 14. Thedevice of claim 1, further comprising at least one fluid channel,wherein a first end of the at least one fluid channel is connected toeach of the plurality of gel reservoirs.
 15. The device of claim 14,wherein a second end of the at least one fluid channel is connected to apressure source configured to provide pressure through the at least onefluid channel to each of the plurality of gel reservoirs.
 16. The deviceof claim 1, wherein the plurality of conductive gel reservoirs isconfigured to collectively store between 3 ml and 20 ml of conductivegel.
 17. The device of claim 1, wherein each of the plurality ofconductive gel reservoirs is configured to store between 0.50 and 5.0 mlof conductive gel.
 18. The device of claim 1, wherein the pressure beingapplied about the perimeter of the seal is between 4 psi and 30 psi. 19.A system for providing therapy to a patient, the system comprising: agarment; a monitor configured to monitor at least one physiologicalparameter of a patient; and a plurality of therapy electrodes operablyconnected to the monitor and disposed in the garment, each of theplurality of therapy electrodes comprising a gel deployment device fordeploying conductive gel onto skin of the patient, the gel deploymentdevice comprising a plurality of gel reservoirs disposed on a substrate,wherein each of the plurality of gel reservoirs comprises a volume ofthe conductive gel and is positioned substantially adjacent to a seal,wherein the seal is configured to release the volume of gel from the gelreservoir in response to a distributed pressure being applied about aperimeter of the seal, and at least one conductive surface configured tocome into contact with the released conductive gel and deliver atherapeutic shock.
 20. The system of claim 19, wherein at least one ofthe plurality of gel reservoirs is oriented on the substrate such thatit surrounds the seal.
 21. The system of claim 19, further comprising atleast one reservoir cluster comprising two or more gel reservoirs. 22.The system of claim 21, wherein the at least one reservoir cluster isconfigured such that the two or more gel reservoirs are positioned abouta center point, thereby defining an open center portion such that theseal of the two or more gel reservoirs is positioned within the opencenter portion of the at least one reservoir cluster.
 23. A system forproviding therapy to a patient, the system comprising: a garment; amonitor configured to monitor at least one physiological parameter of apatient; and a plurality of therapy electrodes operably connected to themonitor and disposed in the garment, each of the plurality of therapyelectrodes comprising a gel deployment device for deploying conductivegel onto skin of the patient, the gel deployment device comprising aplurality of gel reservoirs disposed on a substrate, wherein each of theplurality of gel reservoirs comprises between 0.5 ml and 5.0 ml of theconductive gel and is positioned substantially adjacent to a seal,wherein the seal is configured to release the conductive gel from thegel reservoir in response to a distributed pressure of about 4 psi to 30psi being applied about a perimeter of the seal, and at least oneconductive surface configured to come into contact with the releasedconductive gel and deliver a therapeutic shock.
 24. The system of claim23, wherein at least one of the plurality of gel reservoirs is orientedon the substrate such that it surrounds the seal.
 25. The system ofclaim 23, further comprising at least one reservoir cluster comprisingtwo or more gel reservoirs.
 26. A gel deployment device for use with anelectrotherapy system, the device comprising: a substrate; at least onegel reservoir disposed on the substrate, the at least one gel reservoircomprising a volume of conductive gel and is positioned substantiallyadjacent to a seal, wherein the seal is configured to release the volumeof conductive gel from the at least one gel reservoir in response to apressure being applied to at least a portion of the seal; at least onegel conduit configured to fluidly connect to the at least one gelreservoir and direct flow of the released conductive gel from the atleast one gel reservoir to one or more exit ports disposed on thesubstrate; and at least one conductive surface configured to come intocontact with the released conductive gel and deliver a therapeuticshock.
 27. The device of claim 26, wherein the one or more exit portsare spaced apart on the substrate to provide for even distribution ofthe conductive gel on the conductive surface.
 28. The device of claim26, wherein the at least one conductive gel reservoir is configured tostore between 0.50 and 5.0 ml of conductive gel.